Japan's Most Mysterious Pestilence: Hypotheses on the Morphology of "Coughing Sickness" from the Ninth to Fifteenth Centuries and Potential Connections to Plague

Coughing sickness, known as gaibyô , constitutes Japan's most mysterious pestilence. According to materia medica of the tenth and fourteenth centuries, symptoms included coughing, fever, headaches, hemoptysis, and the production of drivel. This analysis of the available historical sources indicates that coughing sickness comprised many different diseases, and that epidemics occurred during 862–923, 993–1150, and 1228–1408. In the first period, coughing sickness was introduced from the northern Korean/southern Manchurian state of Parhae and caused widespread social and economic dislocation. In the second period, coughing sickness was associated with milder or chronic disease, especially among Japan's aristocracy. In the third period, coughing sickness may have been introduced by the Mongols and presents in ways similar to pneumonic plague. By contrast, the case of the Zen monk Sesson Yûbai possibly presents evidence of the contraction of bubonic plague in Sichuan China, reinforcing the work of such notable scholars as William McNeill, Monica H. Green, and Robert Hymes.