A vector is a living organism that transmits an infectious agent from one host to another, either directly or as part of the agent’s life cycle.
In infectious disease, vectors are usually arthropods such as mosquitoes, ticks, fleas, or certain flies. An infectious agent may be carried on the vector’s body or, in many cases, enter and develop within the vector before being transmitted to another host.
For example, malaria is transmitted by infected female Anopheles mosquitoes. The mosquito is the vector, while Plasmodium is the infectious agent that causes malaria.
QUICK FACT
A vector is not the same thing as the infectious agent. In malaria, the mosquito transmits the parasite; the Plasmodium parasite causes the disease.
COMMONLY CONFUSED WITH
Vehicle: A vector is a living organism that actively transmits an infectious agent, whereas a vehicle is a nonliving medium such as contaminated food, water, or blood through which an infectious agent can be transmitted.
SEE ALSO
- Malaria
- Plasmodium
- Malaria Parasite
- Infectious Agent
- Anopheles Mosquito
- Transmission
- Parasitic Infection