An infection acquired by a patient while in hospital. Because of the high level of antibiotic use in hospitals, some bacteria become resistant – for example, METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA). This makes hospital-acquired infections potentially dangerous and sometimes life-threatening, and is one of the developments that is prompting calls for greater care in the prescribing of antibiotics as well as for higher standards of cleanliness.