1 • Old World Epidemiology to 1500
The fact was that one citizen avoided another, that almost no one cared for his neighbor, and that relatives rarely or hardly ever visited each other—they stayed far apart. This disaster had struck such fear into the hearts of men and women that brother abandoned brother, uncle abandoned nephew, sister left brother, and very often wife abandoned husband, and—even worse, almost unbelievable—fathers and mothers neglected to tend and care for their children as if they were not their own.
What more can one say except that so great was the cruelty of Heaven, and, perhaps, also that of man, that from March to July of the same year [1348], between the fury of the pestiferous sickness and the fact that many of the sick were badly treated or abandoned in need because of the fear that the healthy had, more than one hundred thousand human beings are believed to have lost their lives for certain inside the walls of the city of Florence—whereas before the deadly plague, one would not even have estimated there were actually that many people dwelling in the city.
Giovanni Boccaccio, The Decameron
No people anywhere on earth at any time in human history have been able to avoid frequent and often fatal encounters with disease. In fact, illness and our responses to it constitute one of the great bonds joining us as human beings. And as the above passages illustrate, the terror and hopelessness experienced by individuals who have witnessed massive outbreaks of disease resonate centuries later and could just as easily have been written by someone observing the cholera pandemic of 1900, which claimed some 800,000 victims in India alone, or the present epidemic of AIDS, which has already infected more than 30 million people around the globe.
Outbreaks of disease that spread rapidly and affect large numbers of people within a community are termed epidemics; epidemics that range over a wide geographical area and affect an exceptionally high proportion of a population are sometimes labeled pandemics. Undoubtedly the best-known twentieth-century pandemic began in the spring of 1918, when an outbreak of influenza erupted in the United States. By the time the pandemic subsided a year later, more than 21 million people around the world had perished.
The term virgin soil epidemic describes the initial outbreak of a disease previously unknown or absent from a particular area for many generations; such events usually result in extremely high rates of morbidity and mortality. Virgin soil epidemics of measles, for example, routinely result in morbidity rates of over 90 percent, as was the case when measles first arrived among Pacific Islanders during the second half of the nineteenth century. When a virgin soil epidemic of measles struck the indigenous inhabitants of the Hawaiian Islands in 1848, it claimed the lives of 25 to 30 percent of the total population. Similarly, when measles first appeared in the Fiji Islands in 1875, 20 to 30 percent of the island’s population perished within a period of several months.1 Whenever virgin soil epidemics occur, the simultaneous illness and incapacitation of large numbers of individuals cause many serious problems: a decline or cessation in economic activities, including food production and distribution; the breakdown of political systems; and most important for sick individuals, the disruption of social service networks within families and communities. The sick require basic care—a regular supply of water, nourishment, and clean bedding. When such necessities are not available, the victim’s condition can easily worsen, often resulting in death. When large numbers of the sick begin to die, economic, political, and social crises are magnified, as is the terror of the living who fear the loss of their own health, the loss of loved ones, and ultimately death itself.
That individuals and societies have always seen themselves as distinct from, and often superior to, others is a constant of human history. And this perception of difference, rather than similarity, and the conflicts it creates account for much of the turmoil and suffering in the human experience. But in the realm of biology, few such differences exist: all human populations show remarkable genetic similarity. In fact, geneticists claim that of the one hundred thousand human genes identified to date, 99 percent are shared across human populations. So with regard to the biology of human life, many events, including birth, illness, and death, are truly universal.
Map 1.Regions of the Old World with Distinct Disease Patterns. Map by the author.
Yet another area in which the universal character of the human condition manifests itself can be found in the biological and cultural responses of societies to epidemic disease. Although it is impossible to reconstruct completely the long and complicated history of relations between humans and disease, both archaeological and written sources provide us with enough information to arrive at three conclusions. First, while the responses of particular societies to epidemic disease differ in terms of such specifics as ceremonies of propitiation and remedies employed to cure the sick, in general the emotions experienced, the explanations offered, and the treatments/strategies adopted by affected populations around the world are strikingly similar. Second, massive epidemics of virulent infections posed an ongoing threat to the health and survival of human populations from at least 2000 BCE on. And in fact, disease became such an integral part of the human experience that, unless the outbreak was especially severe, historical records often failed to note its presence. Third, while mortality rates associated with virgin soil epidemics varied depending on the disease, its virulence, and the presence or absence of extenuating factors such as war or famine, the most devastating epidemics in human history have routinely claimed at least 20 to 40 percent of infected populations.
The Universal Nature of Human Responses to Disease
All traditional systems of medicine, whether they originated in East Asia, the Middle East, the Americas, Africa, or Europe, developed over many centuries with two express purposes. The first was preventative: to protect individuals and communities from illness. The second was curative: to aid those who had already succumbed to disease. How societies accomplished those goals varied from one region of the world to another, but in general, all subscribed to holistic theories that emphasized the need for balance and moderation in diet and behavior. And in fact, while some scholars argue that medical systems based on the classification and interpretation of bodily fluids and functions originated with the Greeks and Romans and were later adopted by Islamic societies, others argue convincingly that similar systems, albeit with slight variations, evolved independently in China, Japan, India, and the Americas. For example, according to Greek and Greco-Islamic texts, disease was caused by imbalances among the four humors—blood, phlegm, yellow bile, and black bile—which corresponded to four fundamental qualities—hot, cold, moist, and dry. Indian Ayurvedic medicine identified three humors, while the Chinese developed a similar system that identified heat, cold, humidity, dryness, and wind as causative agents of disease. In the Americas, native Andean medicine was based on an understanding of the three fluids of life—air, blood, and fat—as well as categories of hot and cold. Thus while each system has its own peculiarities, what is most striking are the similarities of classification and interpretation that developed independently in many areas of the world.2
Another feature common to all systems of traditional medicine is a reliance on drug therapy. Because of differences in local plant and animal materials available to medical practitioners, significant regional variations developed. Nevertheless, the philosophy behind the use of drug therapy remained the same—to prevent illness, to alleviate symptoms, and to cure the patient. In most parts of the world, local knowledge regarding herbal and other remedies was extensive; in China, for example, physicians had described some 1,700 drugs by 1126 CE. An eleventh-century Islamic medical text identified more than 720 drugs, and Hindu medicine, which reached its zenith between the first and sixth centuries CE, employed a vast array of herbal cures.3
Fig. 1.The universality of health-care practitioners: (above) a sick lady with her physician and (below) her postmortem, thirteenth century. (Bodleian Library, Oxford)
Another universal characteristic of human responses to ill health involved the explanation of disease causation. In all societies, divine or supernatural intervention was most often cited as the primary cause of disease. Islamic belief that the ultimate cause of illness was the will of God echoed the views of Christians, Confucians, Buddhists, Hindus, native Americans, and Africans. But while deities were ultimately responsible for visitations of disease, their arrival could also be linked to natural disasters, astrological events, and the breaking of social taboos. Traditional Chinese medicine ascribed the causation of disease to the wrath of dead ancestors who had to be placated by sacrifices or to demons who had to be exorcised from the body. Exorcism of disease by means of specialized ceremonies was also commonly practiced in many other societies and frequently supplemented drug therapies. Chinese Buddhists believed that “disease was the result of past sins, and recovery required the confession of these sins. . . . For each transgression, appropriate afflictions were imposed, and days were detracted from one’s alloted lifetime.”4
When bubonic plague struck the Middle East during the fourteenth century, many Moslems “believed that the plague was a punishment visited on man by God because they had strayed from the straight and narrow path of true belief.”5 And Boccaccio’s dramatic description of the Florentine catastrophe in 1348 clearly placed responsibility for the epidemic on “the cruelty of Heaven, and, perhaps, also that of man.”6 Native Americans believed that “all illnesses were the result of biological and cosmic imbalances, [and] cures could be effected only by restoring the system to a state of equilibrium; and that required human intervention through the use of medicinal plants, rituals, and offerings to the gods.”7
The strategies and responses of human populations to massive outbreaks of disease have also been remarkably similar. Because illness was so often attributed to divine providence, many societies developed ceremonies, sacrifices, and processions designed to appease the gods. In Christian communities one of the most common responses to the appearance of epidemic disease was the organization of religious processions during which clergy and laypeople removed the images of saints from their churches and carried them through the streets of the community, chanting and praying for divine mercy. During an epidemic in Paris in 1466, for example, thousands turned out to watch the remains of Saints Crepin and Crepinien being paraded through the streets.8 Similarly, during an epidemic of smallpox that struck Japan in 993 CE, Buddhist monks and a crowd of several thousand organized a procession that marched to the coast in hopes of driving the disease out to sea.9 Ironically, bringing large numbers of people together for public gatherings actually facilitated the spread of contagious illnesses and may, in fact, have worsened epidemics in many cases.
Fig. 2.A fourteenth-century pharmacist and his customer. (Osterreichischen Nationalbibliothek, Vienna)
Among many subjects of the Inca empire of western South America, during epidemics, processions of armed men marched through their communities, attempting to drive out disease. But these processions also served a preventive function. Every year during the month of September people throughout the Inca empire celebrated Citua, one of the four most important festivals of the Inca calendar. Citua was an occasion for purification, “for it represented the expulsion from the city and the district of all the diseases and other ills and trouble that man can suffer.”10 In preparation for the festival, houses were washed and streets cleaned. After a period of fasting and sexual abstinence, families gathered to bathe and rub their bodies with bread, which absorbed illness and removed it from the body. At the same time in Cuzco, four members of the Inca royal family ran out from the center of the city, driving illness in front of them. The ceremony continued the next night, when torches were car...