The state produced by establishment of an infective agent in a suitable host is called?

• A. Infection
• B. Immunity
• C. Contagion
• D. Disease

Answer: (A)

Infection is the establishment and multiplication of an infectious agent within a host. This means the pathogen has entered the body, taken up residence, and begun to replicate, potentially eliciting a host response. It’s possible to have infection without symptoms, since the immune system can control or contain the pathogen. Immunity refers to the host’s defense mechanisms that prevent or limit infection; contagion concerns how infections spread between individuals, not the state inside the host; disease describes the clinical signs and symptoms that arise when infection causes tissue damage or dysfunction. So the state produced by the establishment of an infective agent in a suitable host is infection.