Infection Control Background

To correctly answer questions about infection control, begin by making sure you understand some basic information about etiologic agents and the chain of infection.

An etiologic agent is any pathogen that can cause an infection. Etiologic agents include bacteria, fungi, protozoa, rickettsiae, and helminthes.

There are six elements in the chain of infection:

1. Pathogen: An infectious agent, like a bacteria or virus.
2. Reservoirs: Any environment that is favorable for growth and reproduction of infectious agents. A reservoir may be animate or inanimate. Human systems that can act as reservoirs include blood, respiratory, gastrointestinal, reproductive, and urinary.
3. Portal of exit: A place where the infectious organisms get out of a host. Any of the above-mentioned systems may be portals of exit.
4. Method of transmission: The way an infectious organism is transferred from reservoir to host. This happens in one of three ways: direct contact, indirect contact via a vector, or through the air (airborne).
5. Portal of entry: A place where an infectious agent enters the susceptible host. A portal of entry may also be through a system that can act as a reservoir.
6. Susceptible host: A client, staff member, or other individual at risk for infection.

Now let’s review the most important concepts covered by the Safety and Infection Control subcategory on the NCLEX-RN^® exam.