Taenia
Diphyllobothrium
Echinococcus
Schistoma
1. Taenia (beef and pork tapeworms)
a. Physical characteristics
i. T. solium (pork)
1. Scolex (head) with 4 suckers and a circle of hooks
2. Its segments have 5-10 uterine branches
ii. T. saginata (beef)
1. 4 suckers no hooks
2. 15-25 uterine branches
b. Transmission and disease
i. Taeniasis (intestinal adult worms)
1. Eating raw pork or beef that contains larvae
ii. Contaminated T. solium egg ingestion cysticercosis
iii. Larvae encyst in organs like brain.
iv. T. saginata can not cause cysticercosis
2. Diphyllobothrium (fish)
a. Physical characteristics
i. Longest (13 meters)
ii. Scolex lacks suckers and hook; 2 elongated sucking
grooves
iii. Eggs are oval and have opening called operculum
b. Transmission
i. Ingesting larvae in raw freshwater fish
ii. Cause B12 deficiency so megaloblastic anemia
3. Echinococcus (dog)
a. Physical characteristics
i. Smallest tapeworms
ii. Scolex with 4 suckers and double circle of hooks
iii. Just a scolex and 3 proglottids
b. Transmission
i. Definitive host dogs
ii. Dead-end intermediate hosts humans
iii. Ingestion of eggs contaminated by dog feces
iv. Larvae migrate to organs hydatid cysts form
v. If hydatid cysts rupture anaphylactic shock.
Diphyllobothrium
Echinococcus
Schistoma
1. Taenia (beef and pork tapeworms)
a. Physical characteristics
i. T. solium (pork)
1. Scolex (head) with 4 suckers and a circle of hooks
2. Its segments have 5-10 uterine branches
ii. T. saginata (beef)
1. 4 suckers no hooks
2. 15-25 uterine branches
b. Transmission and disease
i. Taeniasis (intestinal adult worms)
1. Eating raw pork or beef that contains larvae
ii. Contaminated T. solium egg ingestion cysticercosis
iii. Larvae encyst in organs like brain.
iv. T. saginata can not cause cysticercosis
2. Diphyllobothrium (fish)
a. Physical characteristics
i. Longest (13 meters)
ii. Scolex lacks suckers and hook; 2 elongated sucking
grooves
iii. Eggs are oval and have opening called operculum
b. Transmission
i. Ingesting larvae in raw freshwater fish
ii. Cause B12 deficiency so megaloblastic anemia
3. Echinococcus (dog)
a. Physical characteristics
i. Smallest tapeworms
ii. Scolex with 4 suckers and double circle of hooks
iii. Just a scolex and 3 proglottids
b. Transmission
i. Definitive host dogs
ii. Dead-end intermediate hosts humans
iii. Ingestion of eggs contaminated by dog feces
iv. Larvae migrate to organs hydatid cysts form
v. If hydatid cysts rupture anaphylactic shock.
