What defines a nosocomial infection?

A nosocomial infection is specifically defined as an infection that is acquired in a healthcare setting, such as a hospital or nursing home. These infections occur in patients who are receiving treatment for medical or surgical conditions and are not present or incubating at the time of admission. Nosocomial infections can result from various factors associated with healthcare environments, including invasive procedures, the presence of immunosuppressed patients, or the use of antibiotics that can disrupt normal flora.

Understanding this definition is crucial because it highlights the unique challenges associated with infection control within healthcare settings, which is distinct from the other types of infections mentioned in the options.

The other choices reflect different contexts of infection. For instance, infections acquired through travel pertain to illnesses contracted outside of the healthcare system, while infections from contaminated food are related to food safety and hygiene. Finally, infections from soil or water involve environmental factors rather than the clinical settings associated with nosocomial infections. Therefore, the focus on healthcare environments is what clearly defines a nosocomial infection.