ARCANUM
Philip A. Mackowiak, Section Editor

The Origin of Quarantine

Downloaded from https://academic.oup.com/cid/article-abstract/35/9/1071/330421 by guest on 08 April 2020

Figure 1.

Cartoon courtesy of Dr. Theodore E. Woodward, University of Maryland School of Medicine, Maryland

In modern times, the yellow flag depicted in this cartoon
(figure 1) was used to announce that a quarantine against yellow
fever was in effect. Although the use of flags to signal a quarantine is a recent phenomenon, societies have, since ancient
times, used strategies to isolate persons with disease from un-

affected persons. Some of the earliest references to these strategies are found in the books of the Old Testament. In Leviticus,
chapter 13, it is stated that anyone with leprosy remains unclean
as long as they have the disease and that they must live outside
the camp away from others [1, Lev. 13.46]. Numbers, chapter

ARCANUM • CID 2002:35 (1 November) • 1071

 1072 • CID 2002:35 (1 November) • ARCANUM

quarantino, a term derived from the Italian word quaranta,
which means “forty” [5, 7].
The precise rationale for changing the isolation period from
30 days to 40 days is not known. Some authors suggest that it
was changed because the shorter period was insufficient to prevent disease spread [8]. Others believe that the change was related
to the Christian observance of Lent, a 40-day period of spiritual
purification [2]. Still others believe that the 40-day period was
adopted to reflect the duration of other biblical events, such as
the great flood, Moses’ stay on Mt. Sinai, or Jesus’ stay in the
wilderness [9]. Perhaps the imposition of 40 days of isolation
was derived from the ancient Greek doctrine of “critical days,”
which held that contagious disease will develop within 40 days
after exposure [3, 9]. Although the underlying rationale for
changing the duration of isolation may never be known, the
fundamental concept embodied in the quarantino has survived
and is the basis for the modern practice of quarantine.
Paul S. Sehdev
Department of Medicine, Division of Geographic Medicine,
University of Maryland School of Medicine, Baltimore

References
1. Good News Bible. New York: American Bible Society, 1976.
2. Kilwein JH. Some historical comments on quarantine: part one. J Clin
Pharm Ther 1995; 20:185–7.
3. Jewell W. Historical sketches of quarantine. Philadelphia: TK and PG
Collins, 1857.
4. Matovinovic J. A short history of quarantine (Victor C. Vaughan). Univ
Mich Med Cent J 1969; 35:224–8.
5. Stuard SM. A state of deference: Ragusa/Dubrovnik in the medieval
centuries. Philadelphia: University of Pennsylvania Press, 1992.
6. Bolduan CF, Bolduan NW. Public health and hygiene: a student’s manual. Philadelphia: WB Saunders, 1941.
7. Kilwein JH. Some historical comments on quarantine: part two. J Clin
Pharm Ther 1995; 20:249–52.
8. Gordis L. Epidemiology. Philadelphia: WB Saunders, 1995.
9. Foundations of public health: history and development. Baltimore:
Johns Hopkins University Bloomberg School of Public Health, 2001.
Reprints or correspondence: Dr. Paul S. Sehdev, 2222 SW Broadway Dr., Portland, OR 97201
(sehdev@attbi.com).
Clinical Infectious Diseases 2002; 35:1071–2
  2002 by the Infectious Diseases Society of America. All rights reserved.
1058-4838/2002/3509-0008$15.00

Downloaded from https://academic.oup.com/cid/article-abstract/35/9/1071/330421 by guest on 08 April 2020

5, prescribes a duty to expel from camp everyone with a dreaded
skin disease or bodily discharge [1, Num. 5.2]. However, nowhere in these early accounts does the term “quarantine” appear. How, then, did the term become part of the modern
lexicon? The answer to this question can be found in the history
of the black death in Europe.
Beginning in middle of the 14th century, repeated waves of
plague swept across Europe. After arriving in southern Europe
in 1347, plague spread rapidly, reaching England, Germany,
and Russia by 1350 [2]. During this time, it is estimated that
one-third of Europe’s population died. The profound impact
of the epidemic led to the institution of extreme infectioncontrol measures. For example, in 1374, Viscount Bernabo of
Reggio, Italy, declared that every person with plague be taken
out of the city into the fields, there to die or to recover [3].
A similar strategy was used in the busy Mediterranean seaport of Ragusa (modern Dubrovnik, Croatia). After a visitation
of the black death, the city’s chief physician, Jacob of Padua,
advised establishing a place outside the city walls for treatment
of ill townspeople and outsiders who came to town seeking a
cure [5]. The impetus for these recommendations was an early
contagion theory, which promoted separation of healthy persons from those who were sick. Unfortunately, these measures
proved to be only modestly effective and prompted the Great
Council of the City to pursue more radical steps to prevent
spread of the epidemic.
In 1377, the Great Council passed a law establishing a trentino,
or thirty-day isolation period [5]. The 4 tenets of this law were
as follows: (1) that citizens or visitors from plague-endemic
areas would not be admitted into Ragusa until they had first
remained in isolation for 1 month; (2) that no person from
Ragusa was permitted go to the isolation area, under penalty
of remaining there for 30 days; (3) that persons not assigned
by the Great Council to care for those being quarantined were
not permitted to bring food to isolated persons, under penalty
of remaining with them for 1 month; and (4) that whoever did
not observe these regulations would be fined and subjected to
isolation for 1 month. During the next 80 years, similar laws
were introduced in Marseilles, Venice, Pisa, and Genoa [4, 6].
Moreover, during this time the isolation period was extended
from 30 days to 40 days, thus changing the name trentino to