Citation:
A reservoir is a habitat in which an infectious agent normally lives, grows, and multiplies. It can be living organisms or nonliving sites.
Carrier: An individual who harbors the pathogen but does not show symptoms, potentially spreading it to others.
An organism, often an insect, that transmits a pathogen from one host to another.
Fomite: An inanimate object that can carry and transfer pathogens between hosts.