Parasites

Question 1

Are parasites eukaryotes, prokaryotes, or both?

Answer 1

Eukaryotes

Question 2

3 main protozoa?

Answer 2

ameba, flagellates, sporozoa

Question 3

3 main parasite categories?

Answer 3

single celled protozoa, multicellular helminths, macroscopic ectoparasites

Question 4

3 main helminths?

Answer 4

nematodes/roundworms, cestodes/tapeworms, trematodes

Question 5

Why are antiparasitic agents potentially toxic?

Answer 5

targeting eukaryotic processes

Question 6

Main ectoparasite subcategory?

Answer 6

arthropods (i.e. ticks, fleas, lice)

Question 7

What category of parasite can act as vectors or disease agents?

Answer 7

ectoparasites

Question 8

How are protozoa categorized?

Answer 8

by mode of movement

Question 9

What do all sporozoa have in common?

Answer 9

organisms whose adult stage is not motile

Question 10

What kind of parasite is plasmodium?

Answer 10

sporozoa

Question 11

What kinds of parasites are giardia and trichomonas?

Answer 11

flagellates

Question 12

What are the life cycle stages of protozoa?

Answer 12

trophozoite and cyst, some may have additional sexual stages

Question 13

What do trophozoites do?

Answer 13

they’re motile, feeding, and reproducing

Question 14

What do cysts do?

Answer 14

they’re thick walled and surviving in the environment

Question 15

What life cycle stage of protozoa is associated with pathogenicity?

Answer 15

trophozoite

Question 16

Definitive vs intermediate host?

Answer 16

Definitive = where parasite completes sexual phase; intermediate = parasite lives asexually

Question 17

Define reservoir

Answer 17

host that serves as a source of parasite transmission to the population of interest

Question 18

In what stages of life are flukes infectious?

Answer 18

egg, larva, and adult

Question 19

In what stages of life are tapeworms infectious?

Answer 19

larva and adult

Question 20

In what stages of life are nematodes infectious?

Answer 20

larva and adult

Question 21

2 kinds of larvae?

Answer 21

rhabditiform and filariform

Question 22

Which larvae is “early stage”

Answer 22

rhabditiform

Question 23

Which larvae is “later stage”

Answer 23

filariform

Question 24

Which larvae is infectious?

Answer 24

filariform

Question 25

What is the innate human immune response to parasites?

Answer 25

high eosinophil count/Eosinophilia

Question 26

Are eosinophils effective at combating parasitic infections?

Answer 26

No - eukaryotic parasites have evolved to supress, avoid, and deflect

Question 27

What is meant by the "hygiene hypothesis?"

Answer 27

As we decrease the incidence of parasites with modern, more sterile environments, we increase the risk of inappropriate immune response to self-antigens and environmental allergens (immune disease and allergies increase)

Question 28

Helminths vs protozoa - which is considered a more cosmopolitan infection and which is associated with poor countries?

Answer 28

``` Cosmopolitan = protozoans (i.e. Giardia) Poor = helminths (i.e. tapeworms) ```

Question 29

Geographic distribution of vector borne parasites?

Answer 29

Corresponds to geographic distribution and seasonal activities of their arthropods

Question 30

Explain how local intestinal disease works. What kind of organism involved?

Answer 30

trophozoites attach at brush border and injure/irritate, villous atrophy/damage of microvilli or tight junctions may occur, symptoms range from asymptomatic to diarrhea, may even be chronic syndrome