Which term describes the sequence of events in disease transmission: agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host?

Which term describes the sequence of events in disease transmission: agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host?

• A. Transmission Cycle
• B. Epidemic Curve
• C. Infection Pathway
• D. Chain of Infection

Answer: (D)

Think of infection spreading as a chain of events that must connect from one person to another. The six links are the infectious agent, a reservoir where it lives, a portal of exit for the agent, the mode of transmission, a portal of entry into a new host, and a susceptible host. This term best fits because it emphasizes how each link depends on the others, and breaking any one link stops transmission. For instance, eliminating the reservoir, preventing the exit or entry of the agent, blocking transmission pathways, or reducing the number of susceptible individuals all disrupt the chain. Other terms describe related ideas but don’t capture this linked sequence as precisely: a transmission cycle is a broader concept of spread, an epidemic curve charts cases over time, and infection pathway isn’t a standard term. The chain of infection, therefore, specifically describes the connected steps and where to intervene to prevent spread.

Think of infection spreading as a chain of events that must connect from one person to another. The six links are the infectious agent, a reservoir where it lives, a portal of exit for the agent, the mode of transmission, a portal of entry into a new host, and a susceptible host. This term best fits because it emphasizes how each link depends on the others, and breaking any one link stops transmission. For instance, eliminating the reservoir, preventing the exit or entry of the agent, blocking transmission pathways, or reducing the number of susceptible individuals all disrupt the chain. Other terms describe related ideas but don’t capture this linked sequence as precisely: a transmission cycle is a broader concept of spread, an epidemic curve charts cases over time, and infection pathway isn’t a standard term. The chain of infection, therefore, specifically describes the connected steps and where to intervene to prevent spread.