Diseases and Immunology

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Diseases and Immunology

Crossroads. China was always exposed to epidemic dis-eases. Trade along the old silk route, war with the northern barbarians, and travel to and from India and Indochina all helped the spread of smallpox, pulmonary diseases, febrile illnesses, dysentery, and plague. With the emergence of European traders to China’s southeast coast and the increase of international commercial activities in Southeast Asia during the sixteenth century, new epidemic illnesses, such as scarlet fever, cholera, diphtheria, and syphilis, appeared in the region.

Malaria. The mention of malarial fevers initially appeared in medical texts in the seventh century. Temperatures during the Tang period (618-907) were most likely higher than those of today, which meant that the diseases associated with the southern climates, such as malaria, schistosomiasis, and dengue fever, could be found further north. Some specialized treatises in the twelfth century suggested that the miasma of certain regions caused malaria.

Bubonic Plague. The history of bubonic plague in China is a controversial subject. Some scholars believe that it arrived in China in the early 600s, while others suggest the first appearance was in the 1130s in Guangzhou. (It is known that plague epidemics swept through the Roman Empire and present-day Iraq and Iran from the mid sixth century to the late eighth century.) Both of these views are based at least in part on simple descriptions of symptoms, such as congestion of the throat, chills, fever, vomiting, diarrhea, and buboes. A devastating epidemic occurred in China in the early thirteenth century, and it might have been related to the European Black Death at that time.

Smallpox. The first treatises on smallpox appeared in the late eleventh century. Qian Yi, an eleventh-century pediatrician, was among the first to identify smallpox, as well as chicken pox, measles, and scarlet fever. Pediatricians suggested that by that time smallpox had developed into a childhood illness among the Chinese population. The technique of variolation (inoculation with the smallpox virus) using human pox was first practiced in the lower Yangzi (Yangtze) region by the second half of the sixteenth century. Despite the early practice of variolation, smallpox was widespread in China, especially in the North.

Inoculation. The origins of inoculation against smallpox in China are rather mysterious. Daoist alchemists

who lived as hermits in caves possessed the secret of smallpox inoculation in the tenth century. They evidently first brought the technique to public attention after the eldest son of Prime Minister Wang Tan died of smallpox. Wang badly desired to prevent this disease from infecting any other members of his family, so he convened a meeting of physicians, wise men, and magicians from throughout the empire, and it was then that he stumbled upon the treatment.

Delicate Process. Chinese inoculators practiced various methods so that the chances of obtaining the full-blown disease were reduced while the chances of immunity were raised. The primary procedure used was to put the pox material on a plug of cotton, which was then inserted into the person’s nose. The pox was therefore absorbed, by breathing, through the mucous membrane. Inoculators usually chose pox material from the scabs of someone who had been inoculated previously.

Contribution. Traditional Chinese smallpox inoculation was relatively safe, but it did not become widely known and practiced until the period 1567-1572, as indicated by the author Yu Chang in his book Various Thoughts in Medicine, published in 1643. During the seventeenth century the Chinese practice of inoculation spread to the Turkish regions and later to Europe.