Intestinal Parasites

Question 1

Nematodes

Answer 1

Ascaris lumbricoides
Enterobius vermicularis
Necator americanus
Trichinella spiralis 
Trichuris trichiura

Question 2

Cestodes (tapeworms)

Answer 2

Taenia saginata
Taenia solium
Diphyllobothrium latum

Question 3

Ascariasis

Answer 3

fecal-oral transmission
Lives in small intestine of humans, horses, pigs
Can cause colon obstruction
Passed in feces, ingested eggs hatch in duodenum, larvae penetrate intestine wall and enter blood vessels and travels to lung; migrated up trachea, gets swallowed and matures in the small intestine

Question 4

Enterobius vermicularis (Pinworm)

Answer 4

fecal-oral transmission, most common intestinal worm infection
Ingested eggs hatch in cecum, females migrate to perianal skin to lay eggs at night
Use scotch tape prep

Question 5

Necator americanus (hookworm)

Answer 5

Eggs (from humans, pigs, dogs) pass in feces
Larvae penetrate skin of host on the soles of the feet
Circulate to lungs, moves up bronchi and are swallowed
Creeping eruption
Fe- deficiency

Question 6

Trichinella spiralis

Answer 6

uncooked pork, walrus, bear
Encysted larvae in meat is eaten, hatch and penetrate small intestine
Larvae penetrate blood vessels and disseminate to all muscles, remain viable for years

Question 7

Trichurius trichiura

Answer 7

Fecal oral transmission
restricted to a warm climate
people swallow the egg, egg hatches in small intestine, and then attaches to colon and matures to egg laying in 3 months
heavy load causes diarrhea, anemia, rectal prolapse

Question 8

Taenia saginata

Answer 8

beef tapeworm

human is definitive host

Question 9

Taenia solium

Answer 9

Pork tapeworms
human is definitive host
May cause cysticercosis/ neurocysticercosis