Nosocomial refers to anything that originates or occurs within a hospital setting, particularly infections. The term "nosocomial" is derived from the Greek words "nosus," meaning "disease," and "komeion," meaning "to take care of." As such, it describes any illness acquired by a patient while receiving medical treatment. Although its common usage now equates "nosocomial" with hospital-acquired, it specifically refers to infections that develop after a patient has been admitted to a healthcare facility, appearing within 72 hours of admission and not present or incubating beforehand. In the United States and Europe, the bacterium Clostridium difficile is identified as the primary cause of hospital-acquired diarrhea. Meanwhile, Methicillin-resistant Staphylococcus aureus (MRSA) is a variety of staph bacteria that has developed resistance to certain antibiotics and may be contracted during a hospital stay.