• 1) Quarantine: Separation and restriction of movement (ROM) for personnel potentially exposed to a contagious disease but without symptoms of illness.  These personnel may have been exposed to a disease and do not know it, or they may have the disease but do not show symptoms.  This is a command function that is medically supported.
• 2) Isolation: Separation of sick personnel with a confirmed contagious disease or high index of suspicion (i.e. person under investigation) from people who are not sick.  This is a medical function requiring command support.
• 3) Person Under Investigation (PUI): A patient with signs and symptoms consistent with COVID-19 infection and possible exposure to the virus.  In areas where COVID-19 is already widespread, symptoms alone may make the diagnosis of “PUI.”  All PUIs must be isolated.
• 4) Contact Spread: Spread of disease via direct contact with an infected patient or contaminated surface.  Contact precautions aim to mitigate this method of transmission.
• 5) Droplet Spread: Spread of disease via relatively large liquid particles that settle from the air, typically within a few feet.  Droplet precautions aim to mitigate this method of transmission.
• 6) Airborne Spread: Spread of disease via small liquid particles (aerosols) that remain aloft for prolonged periods of time and may travel longer distances.  Airborne precautions aim to mitigate this method of transmission.