The Power of Plagues. Irwin W. Sherman

as were left alive inclining almost all of them to shun and abhor all contact with the sick and all that belonged to them, thinking thereby to make their own health secure … they banded together and formed communities in houses where there were no sick, and lived a separate and secluded life, which they regulated with the utmost care … eating and drinking moderately of the finest wines, holding converse with none but one another … diverting their minds with music and, other delights as they could devise.

The contagious nature of plague led to the belief that the only way security could be achieved was in total isolation of the sick. But despite its being clearly recognized that the enemy was the sick, it was the lack of appreciation that microbes were the cause of infectious diseases that led to the institution of crude and generally ineffectual public health measures. In 1374 the Venetian Republic required that all ships and their crew, passengers, and cargo had to remain on board for 40 days while tied up at the dock; this gave rise to the term “quarantine” (from the Italian word quaranta, meaning “forty”). Soon all European ports restricted entry by quarantine, but the disease continued unabated. “Cordons sanitaires” (literally rings of armed soldiers ordered to guard against the fugitives of disease) restricted the movement of people and may have reduced the spread of plague, but oftentimes the infected individuals were shut up in their homes with the uninfected members of the family, leading to higher mortality. More-effective measures included the burning of clothing and bedding and the burying of the dead in shallow unmarked graves sprinkled with lye. The public, unable to identify the real source of the plague, used “outsiders” as scapegoats. The Black Death also led to societal and religious changes: feudal structure began to break down, the laboring class became more mobile, merchants and craftsmen became more powerful, and guild structures were strengthened. There was also a decline in papal authority, and people lost faith in a Christian church that was powerless to stem the tide of death. The horrors of the plague during this time are depicted in the 1562 painting Triumph of Death (Fig. 4.2). by Pieter Bruegel (1525-1569) and are graphically described in the introduction to Boccaccio’s classic collection of short stories The Decameron and in Albert Camus’ book La Peste (The Plague). It is even depicted in popular movies such as The Seventh Seal by Ingmar Bergman, Monty Python and the Holy Grail, and the movie based on the book Arrowsmith by Sinclair Lewis.

Figure 4.2 Triumph of Death by Pieter Brueghel (1562), Courtesy Wellcome Library, London, CC-BY 4.0

      Though the Black Death was undoubtedly the most dramatic outbreak of plague ever visited upon Europe, it did not disappear altogether. Between 1347 and 1722 plague epidemics occurred in Europe at infrequent intervals. In England the epidemics occurred at 2- to 5-year intervals between 1361 and 1480. In 1656-1657, 60% of the population of Genoa died, half of Milan in 1630, and 30% in Marseilles in 1720. In the Great Plague of 1665, described in the diary of Samuel Pepys (and fictionalized in Daniel Defoe’s Journal of the Plague Year), at least 70,000 Londoners died (out of a population of 450,000).

      The third plague pandemic began in the 1860s in the war-torn Yunnan region of China. Troop movements from the war in that area allowed it to spread to the southern coast of China. Plague-infected rodents, now assisted by modern steamships and railways, quickly spread the disease to the rest of the world. It is estimated that in the three pandemics plague killed more than 200 million people.

      A Look Back

      At the beginning of the 12th century the European population grew quickly after achieving relatively stable numbers during the early Middle Ages. One of the reasons for the unchanging numbers of people was poor harvests and famine, but with the introduction of new crops, windmills, waterwheels, horse collars, and the mold-board plow, agricultural production increased. Money instead of barter began to be used in trade, and with this prosperity new towns grew, and so did the population. But by the 13th century there was ushered in a sustained period of cold winters and rainy summers. Agriculture could not keep up with the population rise, and over the next century famines occurred every few years. The result was poverty and misery, especially in the crowded and filthy cities.

      The second pandemic occurred from 1346 to 1353 and probably originated from the steppes of central Asia, where it was epidemic among small mammals such as marmots and gerbils. Plague spread westward along the trade routes to enter Europe. An outbreak occurred along the Volga River, from where it spread west to the Don River and then down to the Black Sea. By 1347 there were outbreaks in the port cities of Kaffa (present-day Feodosia), Constantinople (present-day Istanbul), and Genoa, and as plague continued to move by ship, it spread via North Africa to Spain by 1348. By this time it had already reached central Europe, including France, Germany, Switzerland, Austria, and even as far as Great Britain. From there it traveled to Scandinavia aboard a ship from London that docked in Bergen in 1349, carrying crew, wool cargo, and plague. By 1351 it was in Poland, and when in 1352 it reached Russia, plague had completed its circuit and a deadly noose had been secured around Europe. In its path the Black Death killed an estimated 17 million to 28 million Europeans, representing ~30 to 40% of the population at the time.

      In 1358, Agnolo di Tura, a citizen of Siena, described the situation:

      Father abandoned child; wife, husband; one brother, another; for this illness seemed to strike through the breath and sight. And so they died. And no one could be found to bury the dead for money or for friendship … and in many places in Siena great pits were dug and piled deep with huge heaps of dead. … And I, Agnolo di Tura, called the Fat, buried my five children with my own hands and so did many others likewise. And there were also so many dead throughout the city who were so sparsely covered with earth that the dogs dragged them forth and devoured their bodies.

The short-term effect of plague was shock and fear. Panic and fright broke the continuity of the existing economic structure and disrupted the routines of work and service. People were terrified, and they deserted the cities and towns. In consequence, communities were thrown into chaos. But the Black Death also had its positive aspects: it contributed to technological advances through the invention of labor-saving devices, as well as a reevaluation of Galenic medicine, and with so many dead the value of labor rose sharply, resulting in greater prosperity among the working survivors.

      Public Health

      More than 2,000 years ago—long before there was Pasteur’s germ theory of disease—the Greek physician Hippocrates of Cos warned that for certain diseases (particularly plague) it was “dangerous to associate with those afflicted.” And in A.D. 549, during an outbreak of plague in Constantinople, the emperor Justinian enacted laws calling for the delay and isolation of travelers coming from regions where there was evidence of this disease. Therefore, in spite of a lack of appreciation that microbes could cause disease, those living in medieval Europe (and dying from the Black Death) recognized that the disease to which they were exposed was contagious and that the only way to preserve the public health would be to isolate the sick totally. When plague reached Europe in 1347, ports on the Adriatic and Mediterranean Seas were the first to deny entry to ships coming from pestilential areas, especially Turkey, the Middle East, and Africa. As early as 1348, Florence, one of the most plague-ridden cities, issued a restriction called quarantine on travelers and goods. The Venetian republic formally excluded infected and suspected ships in 1348, and in 1377 the first official quarantine station was established in Dubrovnik. There persons and ships were isolated on a nearby island for 30 days to await signs of illness or continued good health. Later, other port cities established quarantine stations on shore or on neighboring islands. But even with quarantine, and with 90% of the passengers dying aboard ship, the populations of the port cities were decimated by plague. Quarantine was sometimes employed within the confines of the city itself, and oftentimes the sick