Binary form

For other uses, see Quarantine (disambiguation).

USA president Nixon greeting the Apollo 11 astronauts in NASA's mobile quarantine facility

Signal flag "Lima", called the "Yellow Jack", which when flown in harbour means the ship is under quarantine

A quarantine is a restriction on the movement of people and goods which is intended to prevent the spread of disease or pests. It is often used in connection to disease and illness, preventing the movement of those who may have been exposed to a communicable disease, but do not have a confirmed medical diagnosis. It is distinct from medical isolation, in which those confirmed to be infected with a communicable disease are isolated from the healthy population. Quarantine considerations are often one aspect of border control.

The concept of quarantine has been known since biblical times, and is known to have been practised through history in various places. Notable quarantines in modern history include that of the village of Eyam in 1665 during the bubonic plague outbreak in England; East Samoa during the 1918 flu pandemic; the 1972 Yugoslav smallpox outbreak, and extensive quarantines applied throughout the world during the 2019–20 coronavirus pandemic.

Ethical and practical considerations need to be considered when applying quarantine to people. Practice differs from country to country. In some countries, quarantine is just one of many measures governed by legislation relating to the broader concept of biosecurity; for example Australian biosecurity is governed by the single overarching Biosecurity Act 2015.

Etymology and terminology

The word quarantine comes from quarantena, meaning "forty days", used in the 14th–15th-centuries Venetian language and designating the period that all ships were required to be isolated before passengers and crew could go ashore during the Black Death plague epidemic; it followed the trentino, or thirty-day isolation period, first imposed in 1377 in the Republic of Ragusa, Dalmatia (modern Dubrovnik in Croatia).

Merriam-Webster gives various meanings to the noun form, including "a period of 40 days", several relating to ships, "a state of enforced isolation", and as "a restriction on the movement of people and goods which is intended to prevent the spread of disease or pests". The word is also used as a verb.

Quarantine is distinct from medical isolation, in which those confirmed to be infected with a communicable disease are isolated from the healthy population.

Quarantine may be used interchangeably with cordon sanitaire, and although the terms are related, cordon sanitaire refers to the restriction of movement of people into or out of a defined geographic area, such as a community, in order to prevent an infection from spreading.

History

Ancient

An early mention of isolation occurs in the Biblical book of Leviticus, written in the seventh century BC or perhaps earlier, which describes the procedure for separating out infected people to prevent spread of disease under the Mosaic Law:

"If the shiny spot on the skin is white but does not appear to be more than skin deep and the hair in it has not turned white, the priest is to isolate the affected person for seven days. On the seventh day the priest is to examine him, and if he sees that the sore is unchanged and has not spread in the skin, he is to isolate him for another seven days."