Quarantine is a public health measure which is designed to prevent the spread of infectious disease. When someone or something is quarantined, he she or it is isolated in a secure area so that other people cannot come into direct contact. Once the threat has been cleared, the person or object is released back into general society. Quarantine has a very long history, and also serious ethical and legal implications, as people may be forced into quarantine against their will.
The term derives from the Italian quaranta dei. It comes from the tradition of ordering ships to stand offshore for forty days when they arrived from regions with active plague cases. The idea behind these early quarantines was to establish that no one on board was carrying the plague. Unfortunately, since the disease is carried by fleas and rats, these early quarantines may not have been terribly effective. However, the idea of isolating people who had been exposed to dangerous diseases persisted.
The term of 40 days, however, no longer holds true. A quarantine may be very brief, as in the case of someone who is asked to undergo decontamination after being exposed to something dangerous, or extremely long. Patients in prolonged quarantine are usually provided with reasonably comfortable surroundings and personal services to make the quarantine more pleasant. After the quarantine ends, most of the things the patient was in contact with are destroyed, as they may be contaminated.
When a disease is endemic in a society, quarantine is not employed, because it would be impossible to confine all infected parties. However, when a standalone patient is diagnosed with a highly infectious or dangerous disease, he or she can be put into quarantine to prevent exposing the general population. In addition, the person in quarantine is usually asked to make a list of people he or she has had contact with, so that they can be quarantined as well. Once the disease has run its course or it has become clear that someone is not infected, the quarantined individual is released.
Individual quarantines restrict personal liberties, but benefit society as a whole. Quarantine laws are very rarely enforced in the modern era, partially because of the immense legal and ethical complications which can accompany quarantines. Indeed, some public health institutions actually lack the legal authority to force someone into quarantine, although they can request that someone voluntarily submit to it. While in quarantine, the patient will also be given high quality medical care, both to fight the disease and to encourage the patient to stay.
While some people may question whether or not quarantine is necessary, many medical professionals agree that it really is needed, especially in the case of virulent diseases or drug resistant infections. This is especially true with a disease which has no known cure, since the escape of the disease into the general population could be catastrophic. A short list of infections merit quarantine, and the diseases on the list include things like Ebola, smallpox, and other highly virulent infectious diseases.