Which of the following statements is true regarding the chain of infection?

• A. The chain of infection includes the agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.
• B. Breaking any link in the chain of infection will not affect disease transmission.
• C. The chain of infection is only relevant for viral diseases.
• D. The chain of infection only involves the pathogen and the host.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the concept of the chain of infection. It is a sequence of events that allows the spread of disease from one host to another. The chain includes several key components: the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.
2. Step 2: Identify each component in the chain of infection: the agent is the pathogen causing the disease; the reservoir is where the pathogen normally lives and multiplies; the portal of exit is the path by which the pathogen leaves the reservoir; the mode of transmission is how the pathogen is transferred to a new host; the portal of entry is the way the pathogen enters the new host; and the susceptible host is an individual who can be infected.
3. Step 3: Analyze the statement 'Breaking any link in the chain of infection will not affect disease transmission.' Consider that interrupting any link (for example, eliminating the reservoir or blocking the mode of transmission) can prevent the spread of disease, so this statement is false.
4. Step 4: Evaluate the statement 'The chain of infection is only relevant for viral diseases.' Since the chain applies to all infectious diseases caused by bacteria, viruses, fungi, and parasites, this statement is false.
5. Step 5: Evaluate the statement 'The chain of infection only involves the pathogen and the host.' Since the chain includes multiple components beyond just the pathogen and host (such as reservoir, portal of exit, and mode of transmission), this statement is false. Therefore, the true statement is the one listing all the components of the chain of infection.