Parasites (Stoeckel)

Question 1

T/F: Parasitic disease is prevalent, but infection rates are relatively low.

Answer 1

FALSE

Many are infected, few get diseased!!

Question 2

What parasite has the highest infection prevalence?

Answer 2

Toxoplasmosis

Question 3

What eventually leads to a parasitic disease?

Answer 3

Prolonged, repeated, or high burden infection

Question 4

Which infection is one of the few parasites that can be fatal?

Answer 4

Malaria

Question 5

What are the two major parasite types?

Answer 5

1. Protozoa

2. Helminths

Question 6

T/F: Many parasites require human and nonhuman hosts to complete their life cycles?

Answer 6

TRUE

Question 7

T/F: Protozoa are multi-celled complex organisms.

Answer 7

FALSE

Single-celled eukaryotes

Question 8

T/F: Most species of protozoa are harmless.

Answer 8

TRUE

Question 9

Are Mastigophora motile protozoa?

Answer 9

Yes! They have flagella

Question 10

What is special about Apicomplexa?

Answer 10

They produce sporozoites following sexual reproduction

Question 11

What are the two major infection routes of protozoa?

Answer 11

1. Intracellular: red blood cells, macrophages

2. Extracellular: GI tract (fecal-oral)

Question 12

What characterizes a dead-end host?

Answer 12

The parasite cannot continue life-cycle after infection in dead-end host

Question 13

What characterizes a definitive host?

Answer 13

Reproduction occurs in the host

Question 14

T/F: Protozoa are obligate parasites.

Answer 14

True

Question 15

What is a reservoir?

Answer 15

A source of parasites where they can live, however the source does not directly act in transmission (ex. Dirty water)

Question 16

Where does the developmental stages of a worms life take place?

Answer 16

In insect vectors or animal reservoirs (INTERMEDIATE hosts)

Question 17

How do most worms reproduce?

Answer 17

Sexually

Question 18

How do worms typically cause pathology in a human?

Answer 18

Actually eat body tissue or human has an allergic reaction to byproduct of parasite

Question 19

T/F: With worms, disease is a direct consequence of parasitic replication.

Answer 19

FALSE

Initial inoculum size determines disease

Question 20

What are the two major groups of helminths?

Answer 20

1. Flatworms

2. Roundworms

Question 21

What are the two subdivisions of flatworms?

Answer 21

1. Cestodes (tapeworms)

2. Trematodes (flukes)

Question 22

What is another name for roundworms?

Answer 22

Nemotodes

Question 23

Which type of worms are segmented?

Answer 23

Flatworms

Question 24

What are the most common vectors for parasites?

Answer 24

Arthropods (flies, mosquitos, ticks, etc.)

Question 25

What is a parasite vector?

Answer 25

A source of parasites where they can live and the source is actively involved in transmission (ex. Mosquitos)

Question 26

Is ingestion of contaminated food and water a reservoir or vector?

Answer 26

Reservoir

Question 27

Is penetration of unbroken skin (hookworm) while wading water an example of a reservoir or a vector?

Answer 27

Reservoir

Question 28

Is a mosquito bite allowing a worm to enter the blood stream an example of a vector or reservoir?

Answer 28

Vector

Question 29

T/F: Parasites are susceptible to host antibody and cell-mediated immune responses?

Answer 29

FALSE Most parasites can work around the immune response

Question 30

Why might a parasite enter one person but not another?

Answer 30

Some are cell receptor dependent and some humans lack the receptors for specific parasite infections (ex. Black resistance to malaria)

Question 31

How long does it typically take from infection to clinical manifestations?

Answer 31

YEARS

Question 32

What are some clinical manifestations of schistosomiasis?

Answer 32

GI or urinary tract bleeding for years

Question 33

What are some clinical manifestations of pork tapeworm?

Answer 33

Asymptomatic in intestine -> can enter blood and CNS -> seizures

Question 34

Where is Chagas disease most prevalent?

Answer 34

South AMerica

Question 35

How do many parasites evade the immune system?

Answer 35

1. Coat in host antigens 2. Alter surface antigens 3. Different proteins displayed at different life cycles

Question 36

What does malaria infect in the body?

Answer 36

Red blood cells

Question 37

Where is malaria most prevalent?

Answer 37

Africa

Question 38

What is the definitive host and vector for malaria?

Answer 38

Mosquito

Question 39

T/F: Humans are a definitive host for malaria?

Answer 39

True

Question 40

What is the vector for Babesia?

Answer 40

Tick

Question 41

What parasite is associated with cat feces and cysts in meat?

Answer 41

Toxoplasma

Question 42

T/F: There is a link between toxoplasma Gondi and schizophrenia.

Answer 42

True

Question 43

Where is Leishmania present?

Answer 43

Tropical areas