Veterinary Technician Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

A carrier is an organism that harbors an infectious agent, such as bacteria or viruses, without showing any clinical signs of disease. The importance of a carrier lies in its ability to transmit the infectious agent to other animals or humans, placing them at risk for disease. Carriers can play a significant role in the epidemiology of infectious diseases because they can spread the pathogen without being affected by it themselves.

In contrast, the other choices do not accurately describe this phenomenon. A vector refers specifically to an organism, often an insect, that transmits pathogens from one host to another. A host is an organism that can sustain a parasite or infectious agent and may or may not show signs of disease. A receptor is typically a term used in the context of cellular biology, referring to a molecule on a cell's surface that binds to other molecules (such as hormones or neurotransmitters) and is not commonly used to describe living organisms in the context of infectious disease. Thus, understanding the role of carriers is crucial for controlling the spread of disease in both veterinary and human medicine.