Define nosocomial infection.

A nosocomial infection refers specifically to an infection that is acquired while receiving treatment in a healthcare facility, such as a hospital or nursing home. These infections can occur in patients who are undergoing treatment for other conditions and may arise due to various factors, including compromised immune systems, invasive procedures, or the use of medical devices. Such infections highlight the importance of infection control practices within healthcare settings to minimize risk to patients.

In the context of the other choices, they do not properly define nosocomial infections. While non-pathogenic bacteria are typically harmless, they are not directly associated with the concept of nosocomial infections. The treatment of infections with antivirals pertains more to viral infections specifically, rather than the general context of infections acquired in a healthcare setting. Lastly, while improper hygiene practices can contribute to the spread of infections in healthcare settings, this specific definition does not capture the broader scope of what a nosocomial infection is. Thus, the correct and precise definition is that it is an infection acquired during the course of receiving care in a healthcare facility.