Malaria
Malaria is a tropical disease which takes several forms, caused by different varieties of Plasmodium parasites, often transmitted by mosquitoes. Though very much diminished today, as late as 1900, people as far north as the Kansai region (i.e. Kyoto/Osaka) suffered from malaria; in some areas to the south, such as Okinawa prefecture, malaria was prevalent even as late as the 1960s.
Ailments described as okori 瘧, warawayami 和良波夜美, and eyami 衣夜美 in texts such as the Genji monogatari, Ujishûi monogatari, and Azuma kagami have been identified by scholars as describing, or referring to, malaria.
In the Ryukyu Islands
While the variety of the disease known as "tropical malaria" was likely introduced into the Miyako and Yaeyama Islands from the south, a variety known as "indigenous" malaria is believed to have been introduced to Okinawa in the 12th-14th century by immigrants from Korea and Japan.
Malaria was a significant problem for the Japanese in the Ryukyu Islands and farther south in the Meiji period and into the 20th century. More than five hundred members of the 1874 Taiwan Expedition are believed to have died of malaria.[1] It was, of course, a problem for the locals as well, and many on Okinawa suffered from malaria alongside starvation and other problems as a significant number of people fled central and southern Okinawa to the densely forested Yanbaru region in the north of the island during the 1945 Battle of Okinawa.[2]
Deforestation in Japan and the Ryukyu Islands in concert with urbanization and other aspects of modernity has brought a directly proportional drop in cases of malaria.
References
- Gregory Smits, Early Ryukyuan History: A New Model, Univ. of Hawaii Press (2024), 151-152.
