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Parasites-Helminths
parasites excluding protozoa
Question | Answer |
---|---|
Name the 7 species of clinically significant nematodes. | Enterobius vermicularis, Trichuris trichiura, Ascaris lumbricoides, Necator Americanus, Ancylostoma duodenale, Strongyloides stercoralis, Trichinella spiralis |
What are the 2 molts ovum undergo to become adults? | Rhabdiform and Filariform |
What is the Rhabdiform? | feeding, non-infective form |
What is the Filariform? | nonfeeding, infective form |
The cellulose tape method is used to collect what species? | Enterobius vermicularis |
What is the common name for Enterobius vermicularis? | pinworm |
Which form is the infective form of the pinworm? | ova |
How can male and female pinworms be differentiated? | Females are larger and have a pointy tail while males have a curly tail |
Describe the digestive system of Nematodes. | Complete digestive system with both oral and anal openings |
What is the definitive host for Nematodes? | humans |
What is the common name for Nematodes? | roundworms |
Describe the physical appearance of Nematodes. | cylindrical, non-segmented, tough exterior cuticle |
How many species of Nematodes exist? | ~500K (most are free living) |
Where do the adult female Enterobius vermicularis lay their eggs? | on the perianal folds |
Which age group is pinworm most prevalent among? | children |
Describe the appearance of the pinworm ova. | smooth edge, oval-shaped with one side of the ova being flat, center may appear grainy or the larva may be folded up inside. |
Which Nematode is refered to as the large intestine round worm and is common in dogs and cats? | Ascaris lumbricoides |
How many ova can an Ascaris lumbricoides adult female lay per day? | thousands |
What are the four forms Ascaris lumbricoides can exist in? | corticated or decorticate and fertile or infertile |
Which species of Nematodes migrates through the lungs and matures in the trachea? | Ascaris lumbricoides |
How large can an Ascaris lumbricoides worm get? | As large as a pencil |
What is the danger with Ascaris lumbricoides? | Size and tendency to migrate |
What species of Nematodes is known to cause intestinal blockages? | Ascaris lumbricoides |
What laboratory technique is used in the identification of Ascaris lumbricoides? | Iodine wet mount |
Which form of Ascaris lumbricoides is both the diagnostic and infective form? | Ovum |
What is the common name for Trichuris trichiura? | Whipworm |
What age group is the whipworm most prevalent? | children |
Describe the appearance of the whipworm ovum. | football-shaped with hyaline plugs on each end, similar in size to the pinworm |
What laboratory technique is used to identify whipworm? | Iodine wet mount |
What is one of the scientific name for Hookworm? | Necator americanus (New World) or Ancylostoma duodenale (Old World) |
How can the ova of Necator americanus and Ancylostoma duodenale be differentiated? | they cannot!! |
What is the infective form of Hookworm? | Filariform larva |
Which ovum is known to have a shouldered operculum? | Clonorchis sinensis |
What is the source of cutaneous hookworm? | skin exposure to filariform larvae in dog or cat feces |
What is the clinical picture of cutaneous hookworm? | migration tunnels with intense itching |
What is the source of visceral hookworm? | Ingestion of ova from dog or cat feces |
What is the clinical picture of visceral hookworm? | fever, pneumonitis, hepatomegaly, eosinophilia, CNS infections |
What is the etiology of visceral hookworm? | Toxocara cani and Toxocara cati |
What is key to note about the buccal cavity of the hookworm? | long buccal cavity |
What is another name for thread worm? | Strongyloides stercoralis |
What is the diagnostic form of threadworm? | Rhabditiform |
What is key to note about the thread worm buccal cavity? | short buccal cavity |
Which species diagnostic form is encysted larvae in muscle? | Trichenella spiralis |
What is another name for eye worm? | Loa Loa |
What are the clinical symptoms associated with Trichinella spiralis? | muscle pain and weakness |
How are humans infected by Trichenella spiralis? | ingestion of wild game meat or raw pork |
What are the general characteristics of flatworms? | dorsoventrally flattened, solid body with no cavity, hermaphroditic, life cycles typically involve one or more intermediate hosts |
What are the two types of flatworms? | Cestodes and Trematodes |
What is a proglottid? | individual unit of the strobila which produces eggs. |
How are humans infected by dwarf tapeworm? | when they ingest cysticercoid-infected arthropods |
What is another name for dwarf tapeworm? | H nana |
Which species is known for having a hexicanth embryo and bipolar filaments? | H nana |
What is another name for beef tapeworm? | Taenia saginata |
What is another name for pork tapeworm? | Taenia solium |
Describe the ova of Taenia species. | hexicant embryo with radial striations |
What is the infective form of Taenia species? | cysticercus larvae in muscle |
What does the scolex of Taenia solium look like? | 4 suckers with hooks=armed rostellum |
What does the Taenia saginata scolex look like? | 4 suckers with no hooks=unarmed rostellum |
What is another name for broad or fish tapeworm? | D. latum |
What does the D. latum scolex look like? | has 2 sucking grooves |
How are humans infected by D.latum? | fish ingest plerocercoid larva and humans ingests raw or undercooked fish |
What are the 2 intermediate host of D.latum? | crustaceans and fish |
What do the proglottids of fish tapeworm look like? | broad with clustered uterus |
What does the ova of D. latum ovum look like? | operculum on one end and an avoperculam knob on the other end |
What is sparganosis? | infection in humans by plerocercoid larvae of various diphyllobothriid larvae |
What are general characteristics of Trematodes? | ventral and oral sucking discs, very thin, leaf-shaped |
What is another name for large intestine fluke? | F. buski |
What is the infective form of F. buski? | metacircarie on plants |
What do the F. buski ovum look like? | large and operculated |
What species' infectivity is associated with water chestnuts? | F. buski |
What is another name for liver fluke? | Clonorchis sinensis |
What is the infective form of Clonorchis sinensis? | metacariae in fish muscle |
What is another name for lung fluke? | Paragonomus westermani |
What is the intermediate host for lung fluke? | snail and crayfish |
What does the Paragonomus westermani ovum look like? | operculated on one end and thickening on the other end |
What are other names for schistosomiasis? | bilharziasis, snail fever, swamp fever |
What is Katayama's fever? | immune-mediated against ova |
What is Swimmer's itch? | dermatitis due to cercaria |