Which statement best describes a vector in infectious disease transmission?

Which statement best describes a vector in infectious disease transmission?

• A. A living organism that transmits infection between hosts
• B. An inanimate object that transports pathogens
• C. A chemical that disinfects surfaces
• D. A mode of vaccination

Answer: (A)

A vector is a living organism that transmits infection from one host to another. It isn’t the pathogen itself or a disinfectant, but a carrier that enables the pathogen to move between hosts. Common examples are mosquitoes, ticks, and fleas, which can harbor pathogens biologically (where the pathogen replicates or develops inside the vector) or mechanically (pathogens carried on the vector’s body). This distinguishes vectors from vehicles or fomites, which are inanimate objects that spread pathogens, and from chemicals or vaccines, which do not transmit infections. So a living organism that transmits infection between hosts best describes a vector.

A vector is a living organism that transmits infection from one host to another. It isn’t the pathogen itself or a disinfectant, but a carrier that enables the pathogen to move between hosts. Common examples are mosquitoes, ticks, and fleas, which can harbor pathogens biologically (where the pathogen replicates or develops inside the vector) or mechanically (pathogens carried on the vector’s body). This distinguishes vectors from vehicles or fomites, which are inanimate objects that spread pathogens, and from chemicals or vaccines, which do not transmit infections. So a living organism that transmits infection between hosts best describes a vector.