Interactions between parasites and humans

Question 1

what is a parasite?

Answer 1

an organism that lives on another, at its expense.

Question 2

what is a helminth?

Answer 2

mutlicellualr, eukaryotic organisms.

Question 3

what are nematodes?

Answer 3

round worms.

Question 4

what platyhelminths?

Answer 4

flat worms.

Question 5

what organs can helminths attack?

Answer 5

all the body’s organisms.

Question 6

what is direct infection?

Answer 6

-reproductive stages are released, directly infect new host. e.g people drink water with eggs.

Question 7

what is indirect infection?

Answer 7

• reproductive stages must go through a host.

- e.g. an infected animal is consumed.

Question 8

what is filarisis?

Answer 8

dysfunction of lymphatic system - therefore often leads to secondary infections.

Question 9

what is filarisis caused by?

Answer 9

nematodes.

Question 10

what is filarisis transmitted by?

Answer 10

blood feeding vectors - mosquitos.

Question 11

what can filarisis cause?

Answer 11

long term tissue damage.

Question 12

what are protozoans?

Answer 12

unicellular eukaryotes.

Question 13

what is giardiasis?

Answer 13

• severe diarrhoea
• one of the most common waterborne diseases.
• parasite lives in intestine

Question 14

what are symptoms of giardiasis?

Answer 14

diarrhoea, greasy (floating) stools.

Question 15

treatment for giardiasis?

Answer 15

generally self-limiting.

Question 16

prevention for giardiasis?

Answer 16

good hygiene, avoid contaminated water.

Question 17

what are kinetoplastids?

Answer 17

• flagellated parasites

- trypanosomes.

Question 18

What is american trypanosome also called?

Answer 18

chagas disease.

Question 19

What causes chagas disease?

Answer 19

trypanosoma cruzi

Question 20

how does chagas disease occur?

Answer 20

animal deposits their faeces into a person’s skin.

Question 21

what causes african trypanosomiasis?

Answer 21

-caused by trypanosoma brucei.

Question 22

What is present at the site of the bite?

Answer 22

red sore.

Question 23

what are effects of T. Brucei?

Answer 23

• effects CNS -seizures.

- can be lethal

Question 24

What causes leishmaniasis?

Answer 24

-caused by leishamnia spp.

Question 25

how is leishmaniasis transmitted?

Answer 25

sand-fly bite.

Question 26

pathogenesis of leishmaniasis?

Answer 26

• cutaneous - invasion of skin tissue
• mucosal - invasion of mucosal tissue.
• visceral - invasion of macrophages in liver.

Question 27

What causes acomplexa?

Answer 27

toxoplasma gondii.

Question 28

what causes toxoplasmosis?

Answer 28

undercooked meat, contaminated water, ingeting cat faeces

Question 29

What are symptoms of toxoplasmosis?

Answer 29

flu like symptoms.

Question 30

prevention for malaria?

Answer 30

bed nets, insect repellants, doxycycline prophylaxis.