Part 1

Question 1

Mention the several ways in which arthropods transmits micro-organisms.

Answer 1

1. Mechanical Transmission
2. Biological transmission
3. Horizontal & vertical Transmission
4. Vector incrimination

Question 2

What is Mechanical Transmission?

Answer 2

This is when the pathogen adheres to the body, heads, spines, sticky parts or other structures of insect. In the case of certain insects transmission may be by regurgitation defecation.
Examples: siting flies may transmit pathogens by biting with contaminated mouth part.

Question 3

List the 3 categories of Biological Transmission.

Answer 3

1. Propagative transmission
2. Cyclical transmission
3. Propagative and cyclical transmission.

Question 4

Explain what propagative transmission is.

Answer 4

In this type of transmission, the pathogen multiplies within the body of the vector. But does not undergo any changes in form. For example, most viral disease fall into this category; another example is plague.

Question 5

Explain cyclical transmission.

Answer 5

The parasite undergo several molts in the body of the vector. They stain out as a microfilarice and develops into a infectious larvae, no multiplication takes place within the body of the vector.