In the chain of infection (infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host), what is the most accurate outcome if one link in the chain is missing or effectively broken?

• A. The chain is interrupted, so infection transmission is prevented or significantly reduced.
• B. Infection becomes more severe in the host, but transmission is unaffected.
• C. The infectious agent automatically becomes nonpathogenic and cannot cause disease in any host.
• D. The chain adapts by skipping the missing link, so transmission continues unchanged.

Answer: (A)

Verified step by step guidance

1. Understand the concept of the chain of infection, which consists of six links: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.
2. Recognize that the chain of infection describes the process by which an infectious disease is transmitted from one host to another.
3. Analyze the role of each link: if any one link is missing or effectively broken, the transmission of the infectious agent cannot continue along the chain.
4. Conclude that breaking any link in the chain interrupts the transmission process, thereby preventing or significantly reducing the spread of infection.
5. Note that the other options are incorrect because the infectious agent does not automatically lose pathogenicity, the chain cannot skip links, and infection severity in the host does not affect transmission if the chain is broken.