Introduction to Parasites

Question 1

What is a vector

Answer 1

Organism which acts as intermediate host for parasite
Transmits parasite to next host

Question 2

What are the three classes of parasites?

Answer 2

Protozoa, helminths and ectoparasites

Question 3

Describe the structure of protozoa

Answer 3

Single celled organisms

Question 4

What is the mode of protozoa transmission?

Answer 4

Intestinal parasites - fecal - oral route

Blood parasites - arthropod vector

Question 5

What is the species responsible for malaria?

Answer 5

Plasmodium falciparum

Question 6

What is the vector for malaria?

Answer 6

Anopheles mosquito

Question 7

What is the life cycle of malaria?

Answer 7

Sporozoites injected under skin by mosquito,
Travel through blood & enter liver
Mature in the liver
Re-enter the circulation as merozoites
Invade red blood cells, multiply and lyse cells

Question 8

What is the diagnosis of amoebic dysentery?

Answer 8

Cysts in formed stool - microscopy

Diarrhoea with blood and pus

Question 9

What type of disease is Amoebic Dysentery responsible for?

Answer 9

Intestinal and extra-intestinal infections

Liver abscess in late disease

Question 10

What are the different types of helminths?

Answer 10

Nematodes, Cestodes, Trematodes

Question 11

What are Nematodes?

Answer 11

Round worms

Question 12

What are Cestodes

Answer 12

Tapeworms

Question 13

What are trematodes

Answer 13

Flatworms

Question 14

What is the diagnosis of nematodes?

Answer 14

Press adhesive sellotape against perianal region

Question 15

Name a type of cestode

Answer 15

Tapeworms (taenia saginata/solium)

Question 16

What are the various methods of transmission a tapeworm?

Answer 16

Raw/undercooked meat

Question 17

Where is there a high incidence of Schistosomiasis

Answer 17

Near fresh water, snail is important in the life cycle intermediate host

Question 18

What accompanies a helminth infection?

Answer 18

Eosinophilia
Elevated IgE

Question 19

How is diagnosis of a parasite infection achieved?

Answer 19

Microscopy of parasites cysts and ova

Serology - detection of antibodies

Blood films for malaria

Question 20

Are cultures of parasites possible?

Answer 20

rarely

Question 21

Schistosomiasis is what kind of parasite?

Answer 21

Flatworm (trematode)

Question 22

Ascarius lumbricoides is what kind of parasite?

Answer 22

Round worm (nematode)

Question 23

What kind of parasite infection is leishmaniasis and amoebic dysentry?

Answer 23

Protozoal

Question 24

What are ectoparasites

Answer 24

Parasites which live outside the body

Question 25

What can Helminths cause?

Answer 25

Lead to developmental delay in children.
Bowel obstruction can arise

Question 26

What can pork tapeworms cause?

Answer 26

Cysts to form outside of the gut and cause problems, especially in brain

Question 27

What can Trematodes cause?

Answer 27

Liver failure and bladder cancer if untreated.