Answer:
- source or reservoir of infectious agents
- susceptible host with a portal of entry receptive of the agent
- mode of transmission for the agent
Step-by-step explanation:
Chain of infection is the term that represents a set of related elements (source of infection, route of elimination, route of transmission, gateway) that demonstrates the process of spreading microorganisms that can cause disease in humans and other animals. . The existence of a chain of infection in healthcare settings requires the existence of a source or reservoir of infectious agents, the existence of a susceptible host with an infectious agent receptive entry portal, and the existence of a mode of transmission to the infectious agent.