Vector-Borne Disease Fundamentals

A vector is a living organism that carries and transmits a pathogen from one host to another.

In public health, the most common vectors include:

• ticks

• mosquitoes

• fleas

• rodents (in some contexts)

• other biting insects depending on the disease

The key idea is that the vector itself is part of the chain of transmission.

From a PHI perspective, our main concern is usually prevention.  That prevention often takes two forms.

1) Personal protection and public education

Sometimes the best control measure is helping people protect themselves from exposure.

This can include advice such as:

• Using insect repellent

• Wearing long sleeves and pants

• Installing screens on windows

• Avoiding tall grass or standing water

• Doing tick checks

• Reducing outdoor exposure during peak activity times

2) Environmental prevention

Other times, prevention means addressing the habitat that allows the vector to breed, feed, or harbour.

This may involve:

• Eliminating standing water where mosquitoes breed

• Clearing brush, leaf litter, or overgrown vegetation

• Rodent-proofing structures

• Sealing entry points

• Requiring property owners to remediate harbourage conditions

A good way to think about vector-borne disease questions is this:

How do we reduce contact between people and the vector?
How do we reduce the habitat that allows the vector to thrive?

Those two ideas cover the basics of most vector-borne disease prevention questions.