1260-1600
The final era in the history of disease in Japan before 1600 encompasses the years 1260-1600, which are critical for any real comprehension of the role of pestilence in Japanese history.
Yet this period has not been investigated in detail by historians, although they have access to thousands of unpublished records from this era. Fujikawa (1969) has listed some of the epidemics for this epoch, but, as Jannetta (1987) and Hattori (1971) have pointed out, it is likely that he has missed some. A major difficulty is that reporting mechanisms of disease were hindered by warfare, especially in the periods 133365 and 1460-1550. Thus, records kept at the capital in Kyoto are simply inadequate for the systematic analysis of disease in this period.Despite problems with the sources, however, broad contours can be sketched if this age is broken down into three subperiods: 1260-1420, 1420-1540, and 1540-1600. In the first subperiod, harsh weather and war assisted disease in limiting population growth from 1261 to 1365. There were 29 epidemics over this 105-year span, or one every 3.6 years. From 1366 to 1420, there were 16 epidemics, or one every 3.4 years. The era included smallpox outbreaks in 1314, 1342, 1361, 1365, and 1374, with that of 1365 appearing to have been the only harsh epidemic. Measles is recorded for 1306-7, 1320, 1362, 1380, and 1405 and afflicted mainly children in 1306-7. Influenza struck in 1264, 1329, 1345, 1365, 1371, 1378, and 1407-8, with the attacks of 1365 and 1371 being particularly widespread; Hattori finds strong evidence that, beginning in the 1300s, more people suffered and died from respiratory diseases than smallpox or measles. No epidemics of dysentery or chickenpox are documented (Hattori 1964; Fujikawa 1969).
Perhaps the most important event in the disease history of Japan during the years 1260-1365 was one that did not occur.
In 1274 and 1281, the Mongols attempted to invade the archipelago, but failed both times; in the last invasion, Japan was saved by the intervention of the “divine winds” of a typhoon. As McNeill (1976) has argued, the Mongols carried the plague bacillus from southern China, where it was endemic, to new territories such as China proper and western Europe. If the Mongols had succeeded in their invasion of the islands, then Japan, too, undoubtedly would have suffered from the plague. But Japan remained plague-free, population continued to grow, and the country moved toward an agrocentric society, a condition western Europe avoided in the plague pandemic of 1350-1450.Although the historical record is difficult to read for the era 1421-1540, it appears that disease remained an important factor in demographic change. The period contains 45 epidemics of various descriptions, or one outbreak of pestilence for every 2.7 years, representing an increase over the previous era. Smallpox was particularly active, coming in 1452-3, 1477, 1495, 1523, 1525, 1531, and 1537. In all years excepting 1495 and 1525, however, the disease struck only children. The Portuguese missionary Luis Frois wrote that nearly all Japanese bore pockmarks from smallpox, and he believed that the ailment was more severe among the Japanese than the Europeans (Fujikawa 1969; Hattori 1971).
Measles appeared more frequently, as well, attacking the populace in 1441, 1471, 1484, 1489, 1506, and 1513. The outbreaks of 1471, 1484, and 1512 were harsh, killing many people of all ages. Influenza is recorded as epidemic in 1428 and 1535. Dysentery and chickenpox are not documented. The era 1460-1550 was a period of chronic warfare in Japan, which leads one to suspect a link between the increased social strife and the higher incidence of pestilence (Fujikawa 1969; Hattori 1971).
The period from 1540 to 1600 was an era of great population growth in Japan, which represents the beginning of the Edo demographic explosion.
Evidence of 14 epidemics has survived in the records, or one for every 4.3 years (Fujikawa 1969; Hattori 1971). An epidemic of 1593-4 should probably be linked to Hideyoshi’s invasion of Korea. Smallpox was present only in 1550, and measles struck only in 1578 and 1587. Influenza was reported in 1556, when many children died, but, again, dysentery and chickenpox are not noted in the historical record.In 1543, the first Westerners visited Japan, but unlike notable other areas, Japan did not suffer unduly from this new contact. Only two new diseases entered the archipelago at this time. The first was syphilis, which may also have been a new ailment in western Europe. The first appearance of syphilis in Japan, however, predates contact with Westerners, for it arrived in 1512 (Hattori 1971, citing Fujikawa). The Japanese immediately dubbed syphilis the “Chinese pox” (t∂gasa), and often confused it with both leprosy and smallpox. Frois wrote that syphilis did not cause the embarrassment to the Japanese that it did to the Europeans (Hattori 1971). Its demographic impact was probably small.
The second new disease was introduced directly by the West, specifically by the Portuguese (Boston Globe 1984). Robert Gallo, chief of the Laboratory of Tumor Cell Biology at the National Cancer Institute, has discovered an AIDS (acquired immune deficiency syndrome) virus in the blood of many Japanese living in the southern islands. The virus is called human T-cell IeukemiaZlymphoma virus (HTLV) I and II, and is somewhat different from the AIDS virus found in the United States, which is named HTLV-III. Of the southern Japanese people who are infected with the virus, only 1 person in 80 develops cancer. The rest suffer from a viral disease, characterized by fever, rash, and malaise. Gallo surmises that Portuguese sailors coming to Japan in the 1500s brought infected monkeys and African slaves, who transmitted the disease to the Japanese population. Historical records betray no evidence of this malady.
The other diseases of the early modem period in the West, such as typhus, do not appear to have been transported to Japan until the Edo period. Thus the Japanese were extraordinarily fortunate when compared to the natives of the New World or the southern Pacific, who were subjected to the onslaught of unfamiliar Western parasites. Many inveterate afflictions, such as malaria, beriberi, dysentery, asthma, pneumonia, worms, idiopathic cholera, dropsy, hepatitis, diabetes, chickenpox, rheumatoid arthritis, tuberculosis, and stomach cancer, continued to leave their mark on Japanese culture. Muso Kokushi, the Zen prelate, died of malaria, whereas several Ashikaga shoguns probably had diabetes.