Epidemics, in times past, traveled much more slowly than today. Word of their coming almost invariably preceded a growing number of persons who suddenly developed a disease, just as it does now. But words traveled on paper and by voice, not through instantly appearing electrons, and epidemics traveled by foot, ship, horseback, and carriage, not by aircraft, car, and high-speed train.

People in premodern times understood epidemics through everyday realities that are hard for us to imagine. Before the rise of bacteriology in the nineteenth century, most people would have found it hard to understand concepts such as bacteria, viruses, and other microbes. The outbreak of Covid-19 in late 2019 is premised on the emergence of a novel virus—the appearance of a pathogen with genetic material to which humans had never been exposed. Understanding this fact assumes an understanding of microscopic pathogens that recreate themselves inside the cells of the body, borrowing genetic material from the body to reproduce. In the early nineteenth century, very few persons anywhere in the world understood that the human body consists of cells; the concepts of microorganisms and genetic material would have meant nothing at all (see McGrath and Arya and van der Valk, this series, for examples of pre-modern Tibetan conceptions of epidemics and their agents).

Based on voices from the past and what science tells us today, it seems that the phenomena of disease in the body—the symptoms and signs, the feelings of malaise and pain and overall suffering—are not much different today than the past. Nevertheless, the ways people historically understood what caused all that suffering could not be more different. While this is true across the globe, the Japanese example is especially illustrative.

In premodern Japan, people understood the coming of epidemic disease in one or more different ways. The “or more” is important in that people often used multiple epistemes through which they understood what was happening. The following discusses these understandings through smallpox (hōsō), measles (hashika), and cholera (korera), the three most dangerous epidemic diseases of Edo-period (1600–1868) Japan (Jannetta 1987, 61–172). By then, measles and smallpox had already existed on the Japanese archipelago for centuries. Cholera, on the other hand, was a newcomer. It first appeared in Japan in 1821, spread halfway across the country from Nagasaki to Osaka and Kyoto, only to disappear with the oncoming of cold weather that year. Cholera returned again in 1858 and remained epidemic until at least 1860. It became endemic in parts of the country by the 1870s, and caused eight national epidemics before 1900.

From antiquity through the nineteenth century, measles and smallpox swept the country in waves as the number of susceptible individuals grew in the intervening years, following the previous wave. Once these diseases struck, a large enough percentage of the population became immune, making further spread impossible until enough children who lacked immunity were born to make a city or village susceptible again.

People did not think in terms of viruses and herd immunity when it came to epidemics, but rather that such disease was governed by deities (kami) and buddhas, together called shinbutsu. People believed that the smallpox deity, hōsōgami, could either prevent or cause the disease. The hōsōgami was pleased by the color red, so people placed its image printed in red on their houses along with images of Daruma dolls, owls, certain samurai warriors, puppies, and other things associated with the prevention of smallpox. More generally, people believed that a generic “epidemic deity,” or ekishin, had the power to control other widespread afflictions.

While most Japanese believed that the smallpox deity controlled the disease, many physicians trained in schools of Chinese medicine were aware that inoculation provided some degree of resistance to smallpox. This method, which Chinese physicians had developed, consisted of taking a small amount of material from a pustule on a person with an active case and inserting it subcutaneously into an uninfected person (Leung 2011, 5–8). Although a full-blown case of smallpox was possible, it frequently established life-long immunity. When European physicians introduced the idea of inoculating individuals with cowpox, it found a receptive audience in Japan. This technique consequently became established by the mid-nineteenth century, eventually bringing the disease under control.

Measles, called hashika in modern Japanese, was more greatly feared than smallpox. An early nineteenth century saying went, “Smallpox determines one’s appearance; measles determines one’s life [Hōsō wa mime sadame; hashika wa inochi sadame].” This was especially true for children under the age of five, among whom there was a case fatality rate of up to 25 percent. Generally, physicians could do little for measles other than treat symptoms and make recommendations regarding what foods to eat and avoid. Many people pasted images of associated deities and talismans next to their doors as a mechanism of protection.

Attempts to ward off cholera also arose from pre-existing narratives, such as those based on protection by kami and buddhas. Stories circulated about individuals being shielded from cholera by locusts that a farmer had refused to kill during a major infestation by the insects, and of amulets created by Buddhist priests that were considered effective against the disease. Another common story was that American sailors had caused the 1858 epidemic—which was true—and that a malevolent “American fox” had spread through the land, requiring control by powerful Buddhist and Shinto spiritual powers. At the same time, physicians trained in Western medical techniques looked to European control methods, such as opium and brandy, which was hard to obtain in Japan; physicians trained in the Chinese schools of medicine used herbals and dietary measures. In the end, all of these narrative threads dissolved over the last decades of the nineteenth century (but see Hofer, this series), replaced by the therapeutic and preventive claims of modern allopathic medicine and public health measures.

Traces of these narratives today are unusual, but a past “epidemic deity” (ekishin) (see Figure 1) has reappeared in the shadow of Covid-19. The deity, more accurately called a yōkai or supernatural being, called amabie, was first recorded in 1846 as having appeared in the ocean off the island of Kyushu. It reportedly told the official sent to investigate it that there would be six years of bountiful harvests but there also would be epidemics, and that its picture should be quickly drawn and shown to people, implying that doing so would prevent disease from spreading. During the twentieth century, manga artists, including Mizuki Shigeru, drew their own versions. The amabie has once again appeared, this time associated with preventing the spread of Covid-19 (see Figure 2).

The Japanese Ministry of Health, Labor, and Welfare has included its image on posters urging people to stop the spread of the disease. Numerous variations also can be found for sale in Japan on buttons and stickers, and it appears widely in newspapers, magazines, and websites. While it might be considered a kind of “mascot” figure for the epidemic, amabie also resonates historically as a uniquely Japanese image, reinforcing nativist narratives in a time of national crisis. Probably few, if any, Japanese people believe that it actually will prevent Covid-19, but it offers a source of succor and is a symbol of shared identity in much the same ways that images of the hōsōgami and other epidemic deities also did in the past.