Which of the following correctly lists the steps in the chain of infection in the proper order?

• A. Reservoir, Portal of Exit, Mode of Transmission, Portal of Entry, Susceptible Host
• B. Susceptible Host, Portal of Exit, Reservoir, Portal of Entry, Mode of Transmission
• C. Mode of Transmission, Susceptible Host, Portal of Exit, Reservoir, Portal of Entry
• D. Portal of Entry, Reservoir, Susceptible Host, Mode of Transmission, Portal of Exit

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the concept of the chain of infection, which describes the sequence of events that allows an infectious disease to spread from one host to another.
2. Step 2: Identify the six key components of the chain of infection: Infectious Agent, Reservoir, Portal of Exit, Mode of Transmission, Portal of Entry, and Susceptible Host.
3. Step 3: Recognize that the chain begins with the Reservoir, which is the natural habitat where the infectious agent lives and multiplies.
4. Step 4: Follow the sequence from the Reservoir to the Portal of Exit, which is the path by which the infectious agent leaves the reservoir (e.g., respiratory tract, blood).
5. Step 5: Continue the chain by identifying the Mode of Transmission (how the agent is transferred), then the Portal of Entry (how the agent enters a new host), and finally the Susceptible Host, who is vulnerable to infection.