16 Parasites II

Question 1

What are parasitic infections?

Answer 1

Widespread infections affecting millions to billions of people

Question 2

What has shaped the relationship between hosts and parasites?

Answer 2

An evolutionary arms race

Question 3

What must the host do in relation to parasitic infections?

Answer 3

Control infection without excessive self-damage

Question 4

What is a key characteristic of parasite infections?

Answer 4

Often chronic with high morbidity but lower mortality

Question 5

What have many parasites evolved to evade?

Answer 5

Host immunity

Question 6

What is the connection between high parasite burdens and allergies?

Answer 6

Lower rates of allergies in regions with high parasite burdens

Question 7

What happens to allergy rates when populations with high parasite exposure move to lower parasite areas?

Answer 7

Rates increase over generations

Question 8

What is one possible link between parasites and immune responses?

Answer 8

Parasite exposure may regulate immune responses

Question 9

What is lymphatic filariasis caused by?

Answer 9

Three nematode species, primarily Wuchereria bancrofti

Question 10

How many people are affected by lymphatic filariasis worldwide?

Answer 10

Approximately 50 million

Question 11

What has contributed to the reduction of lymphatic filariasis burden?

Answer 11

WHO prevention strategies

Question 12

Who first identified the worms causing lymphatic filariasis?

Answer 12

Timothy Lewis in 1866

Question 13

What is the life cycle of Wuchereria bancrofti initiated by?

Answer 13

Mosquito injecting L3 larvae during blood meal

Question 14

What do adult female Wuchereria bancrofti produce?

Answer 14

1000+ microfilariae per day

Question 15

What immune evasion strategy involves exploiting host responses?

Answer 15

Mast cell degranulation due to mosquito bite

Question 16

How does Wuchereria bancrofti evade immune recognition?

Answer 16

Produces proteins that block pattern recognition receptors

Question 17

What cytokine levels does Wuchereria bancrofti induce?

Answer 17

High levels of IL-10

Question 18

What does IL-10 regulate in the immune response?

Answer 18

Dampens immune response

Question 19

What chronic condition can result from lymphatic filariasis?

Answer 19

Elephantiasis

Question 20

What causes leishmaniasis?

Answer 20

Approximately 20 species of Leishmania protozoans

Question 21

How is leishmaniasis transmitted?

Answer 21

By sandflies

Question 22

What are the three main types of leishmaniasis disease?

Answer 22

Cutaneous, mucocutaneous, visceral

Question 23

What form does the Leishmania parasite take when injected by a sandfly?

Answer 23

Promastigote (flagellated) form

Question 24

What happens to promastigotes inside macrophages?

Answer 24

Transform into amastigote (non-flagellated) form

Question 25

What immune evasion strategy does leishmaniasis use during initial infection?

Answer 25

Preventing phagosome-lysosome fusion in neutrophils

Question 26

What are M1 macrophages associated with?

Answer 26

Type 1 (Th1) immune response leading to parasite clearance

Question 27

What is the outcome of a Type 2 (Th2) response in leishmaniasis?

Answer 27

M2 macrophages, benefiting parasite growth

Question 28

What does arginase production in leishmaniasis do?

Answer 28

Stimulates parasite growth

Question 29

What is a pathological consequence of cutaneous leishmaniasis?

Answer 29

Replacement of normal tissue with scar tissue

Question 30

What is a significant risk of untreated visceral leishmaniasis?

Answer 30

Typically fatal

Question 31

What common strategies do parasites use to evade host immunity?

Answer 31

*Exploiting normal host responses, avoiding immune recognition, suppressing immune responses, manipulating immune response types*

Question 32

Are parasites common in developed countries?

Answer 32

Yes, even with modern hygiene