What is a contaminated, inanimate object that indirectly transmits infectious agent to a host?

• A. Vehicle
• B. Vector
• C. Reservoir
• D. Source

Answer: (A)

The main idea is indirect transmission through a non-living object that carries a pathogen. This is called a vehicle. A vehicle is any inanimate object or substance that becomes contaminated with an infectious agent and transfers it to a susceptible host. This differs from a vector, which is living (like a mosquito or tick) that transmits pathogens; from a reservoir, which is the place or organism where the pathogen can persist or multiply; and from a source, which refers to where the infection originated rather than the intermediary object of transmission. A familiar example is a doorknob (a fomite) that a pathogen contaminates and then transfers to someone who touches it and touches their mouth or nose. So the contaminating, inanimate object that enables indirect transmission is best described as a vehicle.