What are the basic steps in the chain of infection?

What are the basic steps in the chain of infection?

• A. Pathogen replication, antigen presentation
• B. Diagnosis, treatment, follow-up
• C. Immunization, antibiotic therapy
• D. Portal of exit, mode of transmission, portal of entry, susceptible host; breaking any link reduces spread

Answer: (C)

The chain of infection explains how a disease spreads and where to interrupt it. It includes the infectious agent, its reservoir, the portal of exit, the mode of transmission, the portal of entry, and a susceptible host. Breaking any one of these links can prevent transmission, which is why interventions focus on different parts of the chain—from eliminating the reservoir or exiting point to blocking transmission or reducing the number of susceptible people. The option that lists these links and states that breaking any link reduces spread best captures the idea. Pathogen replication and antigen presentation relate to how the body handles infection rather than how it spreads. Diagnosis, treatment, and follow-up are clinical management steps, not part of the transmission chain. Immunization and antibiotic therapy are preventive or therapeutic tools, not the sequence of steps in transmission.

The chain of infection explains how a disease spreads and where to interrupt it. It includes the infectious agent, its reservoir, the portal of exit, the mode of transmission, the portal of entry, and a susceptible host. Breaking any one of these links can prevent transmission, which is why interventions focus on different parts of the chain—from eliminating the reservoir or exiting point to blocking transmission or reducing the number of susceptible people.

The option that lists these links and states that breaking any link reduces spread best captures the idea. Pathogen replication and antigen presentation relate to how the body handles infection rather than how it spreads. Diagnosis, treatment, and follow-up are clinical management steps, not part of the transmission chain. Immunization and antibiotic therapy are preventive or therapeutic tools, not the sequence of steps in transmission.