Nosocomial infections are infections that have been caught in a hospital and are potentially caused by organisms that are opposed to antibiotics. A nosocomial infection is specifically one that was not present or incubating prior to the patient's being admitted to the hospital, but occurring within 72 hours after admittance to the hospital.

Control: By measuring and comparing the infection rates within a healthcare setting and sticking to the best healthcare practices the Nosocomial infections can be controlled. Centers for disease control and prevention provide the methodology for surveillance of nosocomial infections along with a study of major outbreaks.