Helminths - Trematodes and Cestodes Flashcards
Which Sketchy image represents Taenia genus (cestodes)?
Which Sketchy image represents Schistosoma spp. cercariae (trematodes)?
Identify as many of the marked points in this image as you can.
Note: this is Taenia genus (cestodes).
Identify as many of the marked points in this image as you can.
Note: this is Schistosoma spp. cercariae (trematodes).
What is the scientific name for tapeworms?
Cestodes
The Taenia genus are what kind of infectious agent?
Cestodes
(tapeworms)
What is the intermediate host for Taenia saginata?
Cows
What is the intermediate host for Taenia solium?
Pigs
How can Taenia saginata and Taenia solium be differentiated upon visualization?
Taenia solium has characteristic hooks on its scolex (head)
Neurocysticercosis is an infection of the ______ that can develop following ingestion of Taenia ______ eggs.
Neurocysticercosis is an infection of the CNS that can develop following ingestion of Taenia solium eggs.
How are Taenia solium eggs transmitted?
Via feces-contaminated water
Neurocysticercosis (a CNS infection caused by Taenia solium cestodes) can lead to what signs/symptoms?
Seizures;
brain lesions
Neurocysticercosis (a CNS infection caused by Taenia solium cestodes) leads to what characteristic brain lesions on CT examination?
Swiss-cheese-like lesions
What medication is effective against Taenia infections?
Praziquantel
Treatment of neurocysticercosis (a CNS infection caused by Taenia solium cestodes) requires the addition of what to the praziquantel?
Albendazole
What is Diphyllobothrium latum?
A cestode (tapeworm) transmitted from fish
Diphyllobothrium latum can be transmitted via ingestion of what?
Undercooked fish
Diphyllobothrium latum can cause ____ deficiency, which may lead to ___________ anemia.
Diphyllobothrium latum can cause B12 deficiency, which may lead to megaloblastic anemia.
What is the cestode (tapeworm) with the potential for the longest length (~30 meters!)?
Diphyllobothrium latum
__________ segments of Diphyllobothrium latum can be seen on ______ exam.
Proglottid segments of Diphyllobothrium latum can be seen on stool exam.
What two medications are used to treat Diphyllobothrium latum?
Praziquantel;
niclosamide
What is Echinococcus granulosus?
A cestode (tapeworm)
What are the definitive hosts for Echinococcus granulosus?
And the intermediate hosts?
Dogs;
sheep
Echinococcus granulosus eggs are transmitted via what?
Dog feces
Echinococcal liver cysts show ________ ________ on abdominal CT.
Echinococcal liver cysts show eggshell calcifications on abdominal CT.
What infectious agent is associated with eggshell calcifications on abdominal CT?
Echinococcus granulosus
Echinococcus granulosus infection can lead to _______ _____ formation in the liver.
Echinococcus granulosus infection can lead to hydatid cyst formation in the liver.
Rupture of hydatid cysts caused by Echinococcus granulosus can lead to what?
Anaphylactic reactions
True/False.
Echinococcus granulosus is often characterized by eosinophilia.
True.
What are trematodes?
Flukes (flatworms)
Where are free-living Schistosoma spp. cercariae found?
Aquatic environments (putting swimmers at risk)
_______ are the intermediate hosts of Schistosoma spp..
Snails are the intermediate hosts of Schistosoma spp..
Where do Schistosoma spp. trematodes mature?
The liver
Schistosoma spp. trematodes migrate from the liver in opposition to what blood flow?
Portal blood flow
Name three species of Schistosoma.
- Schistosoma mansoni*;
- Schistosoma japonicum*;
- Schistosoma haematobium*
Describe the various spines seen in the different Schistosoma species.
S. mansoni
S. japonicum
S. haematobium
- S. mansoni* — lateral spine
- S. japonicum* — insignificant spine
- S. haematobium* — large terminal spine
Schistosoma spp. can cause _________’s itch (an allergic reaction to Schistosoma trematodes that manifests as a rash, typically on the _______ _____).
Schistosoma spp. can cause swimmer’s itch (an allergic reaction to Schistosoma trematodes that manifests as a rash, typically on the lower legs).
Schistosomiasis can cause what liver complications?
Jaundice due to cirrhosis and periportal fibrosis
(which may lead to portal hypertension)
What species that causes schistosomiasis of the urinary tract can present with hematuria?
Schistosoma haematobium
Schistosoma haematobium often presents with urinary tract damage and hematuria. To what cancer does it predispose?
Squamous cell bladder cancer
What medication is effective against Schistosoma spp.?
Praziquantel
What are the intermediate hosts of Clonorchis sinensis?
Snails
What is Clonorchis sinensis?
A trematode
(a flatworm)
Clonorchis sinensis infects what part of the body?
The biliary tree (including the gallbladder and bile ducts)
Clonorchis sinensis can cause ________ ________ (inflammation and destruction of bile ducts that can lead to ________ failure).
Clonorchis sinensis can cause sclerosing cholangitis (inflammation and destruction of bile ducts that can lead to hepatic failure).
Clonorchis sinensis infection is a risk factor for what malignancy of the biliary epithelium?
Cholangiocarcinoma
_______ _______ (trematode) infection can cause pigmented gallstones.
Clonorchis sinensis (trematode) infection can cause pigmented gallstones.
Which trematodes’ eggs are operculated?
Clonorchis sinensis;
Paragonimus westermani
What medication is effective against Clonorchis sinensis?
Praziquantel
Paragonimus westermani trematodes infect what organ system?
The lungs
(causing chronic cough and hemoptysis)
What is the intermediate host for trematodes (flukes)?
Snails
Paragonimus westermani is transmitted via what mechanism?
Consumption of raw or undercooked seafood
What medication is effective against Paragonimus westermani?
Praziquantel
