A nosocomial infection is one that:

A nosocomial infection specifically refers to an infection that is acquired while a patient is receiving treatment in a healthcare facility, such as a hospital or nursing home. This type of infection is often a result of the environment of the healthcare setting, where patients may be more vulnerable due to underlying health issues or invasive procedures.

Understanding nosocomial infections is crucial for healthcare workers, as they can impact patient recovery rates and overall health outcomes. Efforts to prevent these infections typically include strict hygiene practices, sterilization of equipment, and careful monitoring of patient care to minimize exposure to pathogens.

The other options highlight aspects of infections but do not capture the specific definition of nosocomial infections. For instance, while immune response can be relevant in various contexts, it does not directly relate to the definition of a nosocomial infection. Similarly, the idea that these infections cannot be transmitted or are spread by infectious droplets speaks to different types of infections or modes of transmission, rather than the context of acquisition in a healthcare environment.