Parasit - Lab Quiz 4

isabellepjk's version from 2017-09-29 14:05

Basics (goes past quiz 4 but good to know for the midterm)

Question Answer
How does a cestode eat things?No digestive system - absorbs things through skin
What are the infective larval stages called in cestodes? Where to they like to hang out?Metacestodes, outside of the intestines in the IH
What is the type of lifestyle of a cestode? Where do they adults live?Indirect, in the GI of the DH
What are the 3 main body parts of a cestode?Scolex ("head"), neck, Strobila ("body")
What is the scolex?Scolex = anterior part attaching to organs (looks like a head)
Has cyclophyllidea - variable suckers
pseudophyllidea - 2 bothria
Rostellum may be present or absent
What is a rostellum?"Crown of thorns" hooks
Describe the features of the scolex of the order Cyclophyllidea4 suckers w/ or w/o rostellum (crown of thorns)
What is the neck?Undifferentiated where segments begin to develop
Describe the features of the scolex of the order Pseudophyllidea? & who is in this group(2)?(Spirometra, Diphyllobothrium) 2 bothria (longitudinal grooves become flattened to form attachment organs
What is the strobila?(The "wormy body" part) Contain proglottids (hermaphroditic segments containing male & female repro organs. Segments at the end of worm contain just gravid uterus)
farther from the neck=more mature
gravid segments are full of eggs (oncospheres)
What are proglottids?Hermaphroditic segments containing male & female repro organs. Segments at the end of worm contain just gravid uterus
Talk through the basic life cycle of a cestode, starting w/ eggEgg gets eaten by IH → metacestode. Metacestode ingested by DH → intestine → body digested away except for scolex & neck → scolex attaches to intestinal wall → start forming segments (strobilia). Segments form w/ mature repro organs → form eggs & sperm → fertilization. Once segments become gravid- detach & eliminated in DH feces → segments disintegrate to release eggs.
What are some variations on their asexual reproduction?Self-fertilization & cross fertilization (b/w segments) can occur
Describe how egg goes to metacestodeEgg contains oncosphere (1st stage larvae) → ingested by IH → egg broken down → oncosphere released → blood/lymph → predilection site → develop to metacestode stage
What is an oncosphere?1st stage larvae, the larvae inside the egg which, once "hatched" inside the IH, will turn into a metacestode
When does most pathogenesis occur in cestode infections?In the METACESTODE/LARVAL STAGE. Which means the INTERMEDIATE HOSTS are the 1s most harmed
What is a Cysticercus? Where is this?In the mammalian IH, it is a single fluid filled cyst w/1 invaginated scolex
What is a Coenurus? Where is this?In the mammalian IH, it is a fluid-filled cyst w/MANY invaginated scolices (each 1 can become mature tapeworm)
What is a Strobilocercus? Where is this?In the mammalian IH. Cysticercus (fluid filled cyst) w/Evaginated (NOT INvaginated) scolex → Already begins to form asexual proglottids (hermaphroditic segments) while in IH→ proglottids digested away by DH (so pure eggs released from DH)
What is a Hydatid cyst? Where is this? WHO does this? What are the types? What is hydatid sand?In the mammalian IH. Genus Echinococcus. Large fluid filled cyst w/many invaginated scolices (free or in bunches). Has a thick, laminated cell wall & germinal epithelium (brood capsules bud off of germinal epithelium). Brood capsules are full of heads (protoscolicieses) & when they burst, it is hydatid sand. The 2 kinds of hydatid cysts are Unilocular or alveolar (alveolar looks like a bunch of grapes)
What is a Cysticercoid? Where is this?In the ARTHROPOD IH. Evaginated scolex embedded in cyst (arthropods)
What is a Tetrathyridium? Where is this?In the invertebrate IH. Worm-like larvae w/ invaginated scolex. Only in mesocestoides in 2ND IH!!

Cyclophyllidea(order) Taeniidae(family)

Question Answer
What does a Taeniidae scolex look like?Scolex: 4 suckers +/- rostellum w/ 2 concentric rows of hooks
Descriptive feature of their proglottids?Unilateral genital pores alternating irregularly
Who can be the DHs of Taeniidae?Carnivores or humans
Metacestodes of Taeniidae can be in which 3 areas of the IH?In liver & peritoneal membranes or skeletal & cardiac muscle
How do you dx dogs & cats for Taeniidae?Oncospheres in feces. Also most have cysticercus (single fluid filled cyst w/1 invaginated scolex)
* How can taenia eggs be released?by proglottid while crawling on the animals fur OR on the surface of the feces

Taenia pisiformes

Question Answer
Who is the DH of T. pisiformes?Dogs & wild carnivores
Dog sheds eggs in feces and the rabbit ingests it, then the dog eats the rabbit
*Who is the IH of T. pisiformes?Rabbits & hares
Dog sheds eggs in feces and the rabbit ingests it, then the dog eats the rabbit
What is the pathology in T. pisiformes?Cysticercus (cyst w/ 1 invaginated scolex) in liver & peritoneal cavity of rabbit, mainly mesentery
How to rememberYou'd be a pissy dog too, if your rabbit mesentery was full of nasty cysts

Taenia ovis

Question Answer
*Who is the DH of T. ovis?Canids & wild carnivores (Fox)
Dog eats sheep heart with cysts
*Who is the IH of T. ovis?Sheep
Dog eats sheep heart with cysts
What is the pathology in T. ovis?In sheep, Cysticercus ovis in cardiac & skeletal muscle
How can you try to prevent T. ovis?De-worm dogs around sheep, dispose of sheep carcass properly
How to rememberOvis mutton (MUSCLE) never looked so a dog <3 <3 <3
What happens if t. ovis lesions are found in a sheep?the whole carcass may be condemned

Taenia hydatigena

Question Answer
What is the weird name for this species of Taenia?Necked bladderworm
DH of T. hydatigena?Canids & wild felids
IH of T. hydatigena?Rums and swine, caribou, moose, elk, dall sheep and black bear
Eggs hatch in the small intestine and the oncospheres reach the liver via the blood. Embryos break out of the portal vessels and migrate in the liver parenchyma for up to 30 days
**What is the name of the larval stage in the IH? What does this metacestode do/cause (pathologically)?Cysticercus tenuicollis. Migrates through liver tissue & encysts on peritoneal membrane & causes hemorrhagic tracks. Can cause hepatitis cysticercosis , black disease/(C. novyi) in intermediate host (rum).
How can you tell if an IH has been previously exposed to T. hydatigena?Previously exposed host has greenish nodules on liver
How to rememberHydatigena will cause black hydrangeas (those poofy blue flowers) to explode from hoofed thing's liver & peritoneum, leaving bloody tracks everywhere. No wonder hoofed things dont like dogs & cats (dogs & cats say, 10/10 colons-taenicolis )
Where will t.hydatigena attach?greater omentum, intestinal mesentery and the serosal surface of organs

Taenia Taeniaeformis

Question Answer
DH of T. taeniformes?Cat
IH of T. taeniformes?Mouse/rodents
Describe (& name) the metacestode of T. taeniformes, & what does it do in the IH?Cysticercus fasciolaris. Cysticercus evaginates at day 42 (becomes Strobilocercus). Strobilocercus (cysticercus w/ evaginated scolex that has already begun to elongate & segment) in liver parenchyma
How to rememberTT was a cat w/ a mouse buddy, but that mouse buddy knew the answer to everything (42), & the strobilocercus popped out & exploded his liver w/ a strobing effect))

Taenia multiceps

Question Answer
DH of T. multiceps?Dog/wild canids
IH of T. multiceps?Sheep, goat (dwarf goat story), sometimes cattle
*Describe the metacestode/pathology of T. multicepsCoenurus cerebralis in cranial cavity and spinal cord of sheep, goats, cattle, and sometimes humans! (Coenurus- Mature cyst in fluid filled cyst w/ clusters of scolices on internal walls). Neurologic signs of progressive space occupation slowly develop, blindness and incoordination→ TRUE GID.
What are some of the signs you see, caused from the pathology?Blindness, incoordination, walking in circles, head pressing, etc. If cyst superficial, softening of skull, death
How to rememberMulti jellyfish in a goats brain will make it go insane
Is it zoonotic?YES
dude from paris had them in his brain, can also be spinal cord, eyes, mm and sq tissues
Canid tapeworms were considered endemic in these regions and the people probably ingested the parasitic eggs through contact with contaminated food or water

Taenia saginata

Question Answer
*DH of T. saginata?human
IH of T. saginata?cattle (mm)
T. saginata life cycle?Eggs or gravid proglottids in feces and are passed into the envrionment
cattle eat the eggs on vegetation
Oncospheres hatch, penetrate the intestinal wall and circulate to the SKELETAL muscles.
oncospheres develop into cysticerci in the muscle
humans are infected by ingested raw or undercooked meat
scolex attaches to the intestine
humans pass proglottids 100 days post infection
*Is it zoonotic?YES AND REPORTABLE
What does it look like and what is the difference?t solis (saginata has no rostellum or hooks)

Taenia solium

Question Answer
*DH of t. solium?human
IH of t solinum?swine
If you ingest taenia solium eggs what do you get?cysticercosis (neuro, occular, pulmonary)
What is the life cycle of t. solium?eggs or proglottids are in the enviro
they are ingested by pigs or humans
oncospheres hatch, penetrate intestinal wall and circulate to the muscles in pigs and humans
develop into cysicerci in STRIATED muscles of pigs or humans
humans can also get infection from eating raw or undercooked meat from an infected host (and the eggs are in there)
scolex attaches to intestine
*What is the primary cause of epilepsy in endemic areas?neurocystercosis from T. solium
How to control the teania species?education, sanitation, meat inspection, cooking meat
*Is it zoonotic?YES AND REPORTABLE
How do you dz?CT, MRI or Rads

Echinococcus granulosus

Question Answer
Definitive hosts of Echinococcus granulosus?Domestic and wild dogs
Get it from eating cysts in organs
*IHsheep, swine, cattle, goats, cattle, horses, camels, HUMANS, moose, elk, deer, and caribou
Get it from ingesting eggs in feces
Is echinococcus granulosa zoonotic?YES
ingestion of eggs leads to human hydatid infection
E. granulosa General?cystic hydatid dz (unilocular)
Smallest tapeworm of domestic animals
Tx/Dx?PAIR (Puncture, aspiration, injections, re-aspiration)
Cysts, rads, US, ELISA, PCR

Echinococcus multilocularis

Question Answer
DH?Foxes, dogs, cats, wild canids ((Ingestion of cysts from IH organs)
* IH?MOUSE aka Small rodents, HUMANS, voles, lemmings, swine, horses, cattle,
Dx in DH?tapeworms on necropsy, feces (PCR because eggs are indentical to taenia so regular fecal won't do)
dx in IH?host species, unilocular vs multilocular cysts
General E. multilocularisalveolar hydatid dz (MULTILOCULAR) -
mainly in the liver and is eventually FATAL
Is it zoonotic?YES
Dog ingested something and developed a hydatid cyst, what did it eat?echinococcus multilocularis

dipylidium caninum

Question Answer
Pruritis ani = scooting
Talk about the mesocestoidesscolex has 4 suckers and no hooks
mature proglottids have a mediodr genital pore
eggs accumulate in a paruterine organ as the segments mature
Is it zoonotic?YES
**How do you treat and how do you discover them?discover around and can rehydrate the egg packets
recd flea tx and control as the dog got it from fleas