The role of disease in Japanese history is a topic that has attracted the interest of Western historians only recently.
The strongest stimulus for the study of disease and its effects on Japan’s premodern society was the publication of a new edition of Fujikawa Yu’s classic Nihon shippei shi in 1969 with a foreword by Matsuda Michio (A History of Disease in Japan, originally published in 1912).
Along with his History of Japanese Medicine (Nihon igaku shi, 1904), A History of Disease in Japan provided historians with a detailed list of many of the epidemics that ravaged the Japanese population in the premodem era, including original sources of information and a diagnosis of many diseases in terms of Western medicine. Hattori Toshiro supplemented and updated Fujikawa’s work in the postwar era with a series of books on Japanese medicine from the eighth through the sixteenth century.William McNeill also kindled interest with Plagues and Peoples (1976), a book that fit the disease history of East Asia into the context of world history. Both William Wayne Farris (1985) and Ann Bowman Jannetta (1987) have investigated pestilence in premodern Japan in detail, but the field is still relatively undeveloped, as compared to work on Western history. The influence of the Annales school of France on Japanese scholars, which began in the late 1970s, may draw more scholars into work on disease, especially for the well-reported but unstudied period between 1300 and 1600.
Data for the study of disease in Japan present both opportunities and frustrations. The quantity of information on disease, especially epidemic afflictions, is better than for most other civilizations, including possibly western Europe. The reason for this is that the Japanese imported the Chinese practice of reporting diseases among the common people around 700. Many of these reports were included in court chronicles in abbreviated form. The custom of reporting epidemics suffered, however, as the links between the provinces and the capital waned after 900, and many outbreaks of pestilence undoubtedly went unnoticed by the aristocrats at court who did the recording of disease.
Moreover, even when the reporting system was operating at its best, the sources often do not provide important facts such as the nature of the disease, the regions afflicted, or levels of mortality inflicted. In addition, local records that would enhance our knowledge of diseases that prevailed are largely lacking before 1100, and the job of ferreting through village and town documents for signs of pestilence after 1100 has yet to be attempted.About the time that the Japanese government borrowed the Chinese custom of recording outbreaks of pestilence, it also borrowed their medical theory. The description, diagnosis, and treatment of disease in premodem Japan almost always derive from Chinese texts. Buddhist scriptures from India also influenced how disease and medicine were perceived in early Japan. It is unclear how much the Japanese knew about disease and its treatment before Chinese and Indian influences. Some medical practices reported during early epidemics may well derive from native roots, as during the Great Smallpox Epidemic of 735-7 (Farris 1985). For the most part, however, the native Japanese view of disease was that it was demonic possession to be exorcised by shamans and witch doctors.
It is important to distinguish between infectious diseases, which can create epidemics, and other afflictions, which, to use McNeill’s terminology (1976), form the “background noise” to history. Japanese sources provide information on a wide variety of diseases, especially when they attacked a statesman, artist, or priest. However, it is often difficult to classify the illness in Western terms. For this reason, the focus of this essay will be chiefly on epidemic outbreaks, with occasional reference to identifiable, noninfectious ailments.
The relationship between disease and Japan’s geography is significant in two respects. First, Japan presents a good case of “island epidemiology” (McNeill 1976). Because of its comparative isolation, Japan remained relatively free of epidemic outbreaks as long as communication with the continent was infrequent.
Consequently, the populations grew dense. However, once an infectious disease was introduced to the archipelago, it ravaged those dense populations that had had virtually no opportunity to develop resistance to it. Thus, immunities were built up only slowly in a process that took centuries.Second, because of Japan’s mountainous terrain, one cannot always assume that an epidemic reached the entire Japanese populace at once. Severe outbreaks undoubtedly afflicted isolated villages and regions even in the Edo period (1600-1868). Certainly, more study of the important relationship between Japan’s topography and transportation routes and disease transmission is needed.
The history of epidemics in Japan until 1600 (when Japan banned travel and trade with most nations) falls into four periods: (1) from earliest times to 700, when little is known about disease; (2) 700-1050, an age of severe epidemics; (3) 10501260, a transitional stage when some killer diseases of the past became endemic in the population; and (4) 1260-1600, a time Oflessening disease influence despite the introduction of some new ailments from the West.