Tissue Nematodes

Question 1

In which class is Trichinella spiralis classified?

Answer 1

Adenophorea

Question 2

What is characteristic of Trichinella spiralis’ esophagus?

Answer 2

long = 2/3 of body length: anterior is thin walled & muscular vs. posterior is surrounded by stichocytes (granular cells w/ digestive enzymes)

Question 3

What is the stichosome and what does it secrete?

Answer 3

posterior to esophagus & stichocytes. secretes?

Question 4

Where do adult Trichinella spiralis’ live in the host?

Answer 4

small intestine

Question 5

Explain how one host ind is the DH & IH in the life cycle of Trichinella spiralis.

Answer 5

female produces L1 not eggs

Question 6

What does ovoviviparous mean?

Answer 6

produces L1 not eggs

Question 7

What type of cells do Trichinella spiralis L1 penetrate once they have left the SI?

Answer 7

skeletal muscle fibers & induce change in muscle

Question 8

What changes occur in a host cell during its transformation into a nurse cell in Trichinella spiralis?

Answer 8

1. loses myofilaments 2. nuclei hypertraply 3. mitochondria degenerate 4. circulatory rate - network of capillaries

Question 9

What symptoms might the host experience during nurse cell transformation in Trichinella spiralis infection?

Answer 9

muscle pain

Question 10

Compare sylvatic & urban trichinellosis.

Answer 10

sylvatic: wild carnivores & prey vs. urban: farms, rats & pigs, pigs eat rats and humans eat pigs

Question 11

What are the 3 phases of Trichinella spiralis pathology?

Answer 11

1. intestinal phase 2. migration phase 3. inflammatory phase

Question 12

What happens during the intestinal phase of Trichinella spiralis?

Answer 12

mild: lesions in intestinal lining, nausea, fever, diarrhea, pain

Question 13

What happens during the migration phase of Trichinella spiralis?

Answer 13

severe (L1s): eye tongue, diaphragm, jaw, chewing, swallowing all have muscle pain. difficultly breathing, chewing, swallowing

Question 14

What happens during the inflammatory phase of Trichinella spiralis?

Answer 14

moderate: nurse cells, strong immune response, heart damage & nervous disorder

Question 15

How is infection with Trichinella spiralis diagnosed?

Answer 15

ELISA: 1. antibodies produced against parastie 2. antigen from stichocytes

Question 16

What is ESA and where is it produced?

Answer 16

excretory secretory antigen from stichocytes

Question 17

How should Trichinella spiralis infection be treated?

Answer 17

albendazole, metbendazole for adult worms. worms don’t live long

Question 18

What populations are most at risk of Trichinella spiralis infection?

Answer 18

people eating undercooked wild game

Question 19

Does cooking or freezing meat control Trichinella spiralis infection?

Answer 19

yes: cook at 170F or freeze at 5F for 21 days

Question 20

What is the normal DH in the Anisakis life cycle?

Answer 20

marine mammals

Question 21

What are the IHs for Anisakis and what stages develop in each host?

Answer 21

1st IH: crustanceans 2nd IH: fish with L3

Question 22

How do humans become involved in Anisakis life cycle?

Answer 22

ingest raw/undercooked fish with L3

Question 23

What pathology can result if a human is infected with Anisakis?

Answer 23

1. acute - intense pain, nausea, vomiting 2. chronic - abescesses, granduloma (host response)

Question 24

How is Anisakis diagnosed in humans?

Answer 24

ELISA

Question 25

What does ELISA detect?

Answer 25

circulting antigen

Question 26

Why doesn't ELISA detect antibodies?

Answer 26

detects parasite secretions from invasion into host tissue

Question 27

How is Anisakis infection treated and prevented?

Answer 27

treatment: self limiting, surgery, albendazole control: candling, cook/freeze meat

Question 28

In which class is Dracunculus medinensis classified?

Answer 28

secermenteo

Question 29

What is the common name of Dracunculus medinensis?

Answer 29

guinea worm, firery serpent

Question 30

How is Dracunculus medinensis transmitted?

Answer 30

L1 is eating by copepod L3 infects humans when they drink infected water

Question 31

Where does the female Dracunculus medinensis live?

Answer 31

skin of humans host

Question 32

Where does female Dracunculus medinensis lay eggs?

Answer 32

subcutaneous tissues of infected humans

Question 33

What causes Dracunculus medinensis blister to form?

Answer 33

immune response by host

Question 34

How do Dracunculus medinensis L1s leave the host?

Answer 34

water causes blister to rupture and L1s enter the water

Question 35

What is the IH in Dracunculus medinensis?

Answer 35

copepods

Question 36

Where do the Dracunculus medinensis adults live?

Answer 36

skin of legs

Question 37

Describe the pathology caused by Dracunculus medinensis.

Answer 37

1. migration - immune rxn to parasite waters 2. blister - secondary infection 3. non emergent worms, didn't make it to skin die & calcified in or near joints and cause arthritis

Question 38

How is Dracunculus medinensis infection diagnosed and treated?

Answer 38

diagnosed: blister with worm treatment: small stick to wind worm: Caduceus

Question 39

In what parts of the world is Dracunculus medinensis found?

Answer 39

areas with drought because water is concentrated

Question 40

Does eradication of Dracunculus medinensis seem possible?

Answer 40

yes: projected to be 1st parasite and 3rd disease to be eradicated

Question 41

What is the Carter Center doing in the fight against Dracunculus medinensis?

Answer 41

1. education 2. treat ponds w chemicals (temephos) 3. funding and gov assistance 4. water wells 5. filter clothes 6. medical supplies 7. pipe filters

Question 42

What is the parasitologist's dilemma?

Answer 42

eradication of parasite may lead to lower host death rate but if this is not matched with lower birth rate -> consequences to quality of life