Helminths

Question 1

Helminths

Answer 1

Divided into 2 phyla
Flatworms
Roundworms/Nematodes

Question 2

Cestode

Answer 2

Tapeworm

Adult body consists of a scolex (head) and strobila (body) made from progottids in series

Question 3

Scolex

Answer 3

Anterior end of a tapework, typically has 4 suckers and might have a rostellum

Question 4

Suckers

Answer 4

Cup-shaped structures that aid in attachment to intestine wall

Question 5

Rostellum

Answer 5

Fleshy extension that may or may not be armed with hooks

Question 6

Strobila

Answer 6

Tapeworm body made of serial proglottids

Question 7

Proglottid

Answer 7

Individual segment

Each contains male and female organs for reproduction

Question 8

Hexacanth embryo/Onchosphere

Answer 8

Motile, first larval stage armed with three pairs of hooklets.
Egg contains an onchosphere surrounded by an embryophore

Question 9

Cysticercus/Larva

Answer 9

Larval stage of Taenia and similar species.

Scholex with fluid-filled cyst, found in tissues of hosts

Question 10

Cysticercoid/Larva

Answer 10

Larval stage of Hymenolopsis nana and similar species

Scholex with cyst with litter or no fluid

Question 11

Coracidium

Answer 11

Ciliated larval stage of Diphyllobothrum latum

Emerges when egg is exposed to water

Question 12

Hyatid cyst

Answer 12

Larval stage of Echinococcus granulosus

Question 13

Taenia saginata diseases and transmission

Answer 13

Cestode
Transmitted from cows
Causes Taeniasis, mild abdominal symptoms

Question 14

Taenia solium diseases and transmission

Answer 14

Cestode
Transmitted from pigs
Can develop cysticercosis as a sequellae to Taeniasis

Question 15

Cysticercosis

Answer 15

Development of cysticerci in various sites in the body

Greatest concern is cerebral cysticercosis - seizures, mental disturbances, sudden death

Question 16

Diphyllobothrium latum diseases and transmission

Answer 16

Cestode
Transmitted from fish
Causes diphyllobothriasis
Can be a long-lasting infection, may be asymptomatic or cause abdominal discomfort.
May cause Vitamin B12 deficiency with pernicious anemia

Question 17

Trematodes

Answer 17

Flukes

Complex life cycles, often involve snail intermediate hosts

Question 18

Fasciolopsis buski diseases and transmission

Answer 18

Large intestinal fluke
Transmitted via pigs and freshwater plants
Causes fasciolopsiasis
Most infections light and asymptomatic, but can cause diarrhea, etc.

Question 19

Nematodes

Answer 19

Roundworms
Can be very long
Have highly developed reproductive system

Question 20

Enterobius vermicularis diseases and transmission

Answer 20

Called pinworm or seatworm
Common infection in schools
Most common helminthic infection in US
Causes Enterobiasis - perianal pruritus (itching)
Transmitted fecal/oral

Question 21

Ascaris lumbricoides diseases and transmission

Answer 21

Large roundworm "Roundworm of Man"
Most common worldwide helminthic infection
Causes Ascariasis
Mature in intestine, lungs.
Pulmonary symptoms, intestinal symptoms

Question 22

Strongyloides stercoralis diseases and transmission

Answer 22

Threadworm (roundworm)
Only females are parasitic in humans
Strongyloidiasis
GI symptoms
Pulmonary symptoms
Causes eosinophilia