test 2 Diphyllobothrium latum Flashcards
Describe the life cycle of Diphyllobothrium latum.
Unembryonated eggs are passed in the feces. In water the eggs hatch and the coracidium comes out. Coracidia get eaten by small crustaceans. Inside the crustacean the coracidium becomes a procercoid. The crustacean is then eaten by a fish. Inside the fish the procercoid becomes a plerocercoid. This small fish can be eaten by a bigger fish (paratenic host) and the parasite survives and remains the same plerocercoid. If a human eats a raw or undercooked infected fish then the parasite develops into a worm in their small intestine, completing the cycle.
What is the relation of D latum to jewish housewives?
the jews have a dish they make called gefilte fish. the woman making it would taste parts of the raw fish to see if the seasoning was right. Once it was right they would cook the fish. They would get infected by D. latum while their family wouldnt as their families would be eating cooked fish. refered to as jewish housewives disease.
Where do the adult D. latum live? How long can they get? How long do they live for?
Live in the small intestine, specifically the ileum. Can get up to 25 meters. live for about 20 years.
Describe the proglottids of D. latum.
Proglottids are wider than they are long. Stay attached to the worm until the eggs pass.
Describe the eggs of D. latum.
operculum and knob. around 1 million can be passed per day (10^10 per lifetime). When it gets in fresh water the operculum opens and the coracidium swims out.
What type of water is D. latum found in?
fresh water. Dont survive very well in salt water
What is the epidimiology of D. latum?
Most common in scandanavian countries. about 9 million people affected worldwide, mostly people who eat undercooked or raw fish. small number of people can pass infection to alot of people.
What are the clinical manifestations of a D. latum infection?
infections are usually asymptomatic. can have abdominal cramps with multiple infections. Pernicious anemia can occur as the worm will take up alot of vit. B12. some neurological manifestations can occur.
What goes into a laboratory diagnosis of D. latum infection?
Eggs or proglottids in the stool. macrocytic anemia
Name the treatment for, and the prevention of D. latum infection.
Praziquantel. Thoroughly cooking fish. freezing at -10 for 2 days. sanitary disposal of human feces.
What is the disease when a human is the intermediate host for D. latum?
Sparganosis
Describe sparganosis
Basically the human takes the place of the fish in the cycle. Human gets infected by the plerocercoid and it migrates around the body. often times it gets behind the eye and can travel to the brain. Often people get it by putting infected frog skin on their eye. frog skin as amphipathic peptides on it with antimicrobial properties.
Define cysticercus.
Larval stage of many tapeworms. contains a fluid filled sac with the scolex invaginated in.
Define cysticercoid.
scolex is surrounded by hard tissue. has a tail.
Describe Hymenolepis nana life cycle.
Embryonated eggs are passed in the stools. Can take one of two routes. An insect will eat the eggs where they will develop into the cystecercoid. the insect will be eaten by a rat which will get infected passing eggs. the eggs can also be eaten by humans. Doesnt require an intermediate host. adult develops in small intestine. autoinfection can occur if the eggs remain in the intestine.
