Parasitic infection

Question 1

What are the 2 main types of parasites?

Answer 1

Protozoa and metazoa.

Question 2

Name 5 features of protozoan parasites

Answer 2

1. Unicellular
2. Eukaryotic
3. Can replicate within the host
4. Have short generation times
5. Normally cause acute infections but can be chronic

Question 3

Which animals are most at risk of protozoan infection?

Answer 3

Young, old, pregnant or lactating animals, or immuno-compromised animals.

Question 4

Name 6 features of metazoan parasites

Answer 4

1. Multi-cellular
2. Rarely multiply in host, eggs excreted in faeces
3. Level of disease depends on the parasitic burden
4. Have long generation times
5. Normally cause chronic infections
6. Host immunity can develop

Question 5

What are the 2 main routes of parasitic infection?

Answer 5

Direct and indirect.

Question 6

What is meant by ‘direct transmission’?

Answer 6

Infection is acquired from the environment and an intermediate host/vector is not required for transmission.

Question 7

What is meant by ‘indirect transmission’?

Answer 7

An intermediate host/vector is required for transmission.

Question 8

Why is it important to understand parasitic life cycles? (5 reasons)

Answer 8

1. How parasite is transmitted
2. Where in the host the parasite locates
3. How it causes disease, and at which stage of it’s life cycle it does so
4. How to diagnose infection
5. How to control infection