quarantine

—quarantinable, adj. —quarantiner, n.

/kwawr"euhn teen', kwor"-, kwawr'euhn teen", kwor'-/, n., v., quarantined, quarantining.

n.

1. a strict isolation imposed to prevent the spread of disease.

2. a period, originally 40 days, of detention or isolation imposed upon ships, persons, animals, or plants on arrival at a port or place, when suspected of carrying some infectious or contagious disease.

3. a system of measures maintained by governmental authority at ports, frontiers, etc., for preventing the spread of disease.

4. the branch of the governmental service concerned with such measures.

5. a place or station at which such measures are carried out, as a special port or dock where ships are detained.

6. the detention or isolation enforced.

7. the place, esp. a hospital, where people are detained.

8. a period of 40 days.

9. social, political, or economic isolation imposed as a punishment, as in ostracizing an individual or enforcing sanctions against a foreign state.

v.t.

10. to put in or subject to quarantine.

11. to exclude, detain, or isolate for political, social, or hygienic reasons.

[1600-10; < It quarantina, var. of QUARANTENA, orig. Upper It (Venetian): period of forty days, group of forty, deriv. of quaranta forty L quadraginta]

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Detention of humans or animals suspected to have communicable disease until they are proved free of infection.

The term is often used interchangeably with isolation (separation of a known infected individual from healthy ones until the danger of transmission passes). It derives from the 40-day (quarantina) isolation period instituted in an attempt to prevent spread of plague in the Middle Ages. Though appropriate in some cases (e.g., diphtheria), it is ineffective for diseases that are spread by other means (e.g., plague) or are contagious before symptoms appear. In some cases, contacts (e.g., the family of a hepatitis patient) are notified, educated on precautions, and monitored for development of illness. Quarantine is more often applied to animals (e.g., for rabies).

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▪ preventive medicine

Introduction

      the detention or restraint of humans or other creatures that may have come into contact with communicable disease until it is deemed certain that they have escaped infection. In the vocabulary of disease control the terms quarantine and isolation are used interchangeably. In the strictest sense, however, isolation is the separation of an infected individual from the healthy until he is unable to transmit the disease.

Early practices.

      The earliest recognition that diseases might be communicable led to extreme measures designed to isolate infected persons or communities. Fear of leprosy caused wide adoption of the control measures set out in Leviticus 13, namely, isolation of the infected and the cleansing or burning of his garments. Against acute, highly fatal diseases like bubonic plague, which spread rapidly, attempts were made by healthy communities to prevent the entry of goods and persons from infected communities.

      In the 14th century the growth of maritime trade and the recognition that plague was introduced by ships returning from the Levant led to the adoption of quarantine in Venice. It was decreed that ships were to be isolated for a limited period to allow for the manifestation of the disease and to dissipate the infection brought by persons and goods. Originally the period was 30 days, trentina, but this was later extended to 40 days, quarantina. The choice of this period is said to be based on the period that Christ and Moses spent in isolation in the desert. In 1423 Venice set up its first lazaretto, or quarantine station, on an island near the city. The Venetian system became the model for other European countries and the basis for widespread quarantine control for several centuries.

      In the 16th century the system was extended by the introduction of bills of health, a form of certification that the last port of call was free from disease; a clean bill, with the visa of the consul of the country of arrival, entitled the ship to free pratique (use of the port) without quarantine. Quarantine was later extended to other diseases besides plague, notably yellow fever, with the growth of American trade, and cholera, which was particularly associated with the pilgrimages to Mecca.

      By the mid-19th century the practice of quarantine had become a considerable nuisance. The periods of quarantine were arbitrary and variable from country to country, and there were instances of perverse and bureaucratic application of the quarantine regulations. The disinfection of letters and rummaging of papers could be an excuse for political espionage, and the opportunities for bribery and corruption were frequently exploited. Great discomfort and delay was caused to travelers; the prison reformer John Howard (Howard, John) had, in 1786, deliberately sailed from Smyrna to Venice in a ship with a foul bill of health so that he could gain firsthand experience of lazarettos; his account (An Account of the Principal Lazarettos in Europe [1789]) presents a depressing picture.

International cooperation.

      General dissatisfaction with quarantine practice led to the convening of the first international sanitary conference in Paris in 1851. The arguments were conducted at two levels. Commercially, the conflict was between the countries with considerable vested interests in quarantine and the major maritime nations, which favoured its abolition; medically, the opposition was between the “contagionists,” who believed that diseases like cholera and plague were transmitted from person to person, and the “miasmatists,” who thought that they were caused by infected atmosphere and that the remedy was sanitation, not quarantine. Despite these differences, agreement was reached on some important general principles for the standardization of quarantine procedures. The convention and regulations were not generally ratified, however.

      In the next 50 years a succession of sanitary conferences, with better understanding of the epidemiology of communicable disease, reached some agreement on the maximum permissible measures of control and on the removal of the most irksome restrictions of quarantine practice, but the accord reached by the 11th conference, at Paris in 1903, was the first really effective measure to be signed. Out of it came, in 1907, the Office International d'Hygiène Publique (“International Office of Public Health”), the forerunner of the World Health Organization. (The forerunner of the Pan American Sanitary Bureau had been established five years earlier, in 1902).

Present practices.

      Today, isolation of persons is practiced much less rigidly or extensively than formerly in the control of communicable disease. It may be appropriate in some cases; some physicians, for example, suggest that known asymptomatic carriers of the diphtheria bacillus be isolated during antibiotic treatment, and patients with active pulmonary tuberculosis may be temporarily segregated in hospital in order to prevent the infection of persons thought to be susceptible to the disease. It is recognized, however, that isolation may fail for a variety of reasons. It is ineffective in diseases that are transmitted by an intermediate carrier—e.g., the mosquito in yellow fever and malaria. In plague, isolation is important to prevent person-to-person spread but does not have any effect on the main route of infection—by bites of the rat flea. It is inappropriate to isolate human cases of a disease, such as brucellosis, that is usually acquired by contact with infected farm animals or their products. Even for diseases in which it may protect individuals, isolation will often have little effect on the general epidemic; this may be, as in measles, because infectivity precedes the appearance of the characteristic feature, the rash, by a few days, or, as in polio virus infections, because a number of persons are carriers, harbouring the disease agent without discernible illness. The difficulty of recognizing potentially infective persons often makes isolation impracticable even in situations in which it could be appropriate.

      Quarantine is much modified in modern practice because of the better understanding of communicable disease. In its purest form it is applied to animals, as in the control of rabies. In the control of human disease the common practice is surveillance of contacts, with, possibly, daily reporting to a doctor to get prompt recognition of illness but without restricting movement; such a policy, coupled with other control measures, is generally accepted. In some instances modified quarantine is imposed: adult contacts of typhoid (typhoid fever) should be excluded from food handling until repeated bacteriological examination of feces and urine has shown them to be free of the disease. At one time susceptible children exposed to measles were kept home from school, but the practice was declining even before the widespread use of measles vaccines.

      Quarantine and exclusion of plants and of plant products are still widely practiced in accordance with international agreements.

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