Deck 52: Intestinal Cestodes

Question 1

The double-pored tapeworm,Diphyllobothrium caninum,consisting of many small proglottids,measures 10 to 70 cm in length as an adult.The scolex contains four suckers and an armed rostellum.The intermediate host in which infective cysticercoids develop is the:

A)dog.
B)cat.
C)flea.
D)human.

Answer 1

C
D.caninum,the cat or dog tapeworm,is a double-pored tapeworm consisting of many small proglottids.As the tapeworm matures,the proglottids break off and pass in the stool.Adult tapeworms measure 10 to 70 cm in length.The scolex contains four suckers and an armed rostellum.Ingestion of an infected flea may result in D.caninum infection.The flea is the intermediate host in which infective cysticercoids develop;humans,dogs,and cats are the reservoir hosts.

Question 2

The T.solium organism,which causes cysticercosis and can grow to be 1.5 to 8 meters long,contains 7 to 13 lateral uterine branches along the proglottid.The intermediate host is:

A)dogs.
B)cats.
C)pigs.
D)cattle.

Answer 2

C
T.solium,the pork tapeworm,is the intestinal cestode capable of causing serious pathologic damage to the human host.Humans serve as the definitive host,whereas pigs serve as the intermediate host.Humans can also serve as the intermediate host.T.solium may result in an intestinal infection,in which the larvae mature and reside in the small intestine for up to 25 years.The organisms can grow to be 1.5 to 8 meters long and produce over 1000 proglottids,each containing approximately 50,000 eggs.Cysticercosis is the extraintestinal form of the disease and can be significantly more severe.The disease is life threatening if the organism invades the central nervous system.

Question 3

The Diphyllobothrium latum tapeworm can reach up to 10 meters in length and can have more than 3000 to 4000 proglottids.The definitive host and reservoir host,respectively,are:

A)fish and copepods.
B)crustaceans and humans.
C)copepods and crustaceans.
D)humans and fish.

Answer 3

D
The organism D.latum is a freshwater broad fish tapeworm and the largest human tapeworm.Adult tapeworms have been known to reach up to 10 meters in length,with more than 3000 to 4000 proglottids,and reside in a host for 30 years or longer.Fish serve as the reservoir host,with humans serving as the definitive host.

Question 4

A stool specimen is examined,and the following characteristics are observed:
·15 to 18 lateral branches on each side
·Scolex with four suckers
·No hooklets
The intermediate hosts of this tapeworm are:

A)cattle.
B)humans.
C)cats.
D)swine.

Question 5

The mode of infection for which of the following organisms is the ingestion of cysticercoid in an infected arthropod or by the direct ingestion of the egg? Autoinfection may also occur.

A)D.latum
B)Hymenolepis nana
C)Taenia saginata
D)Taenia solium