The Invisible Traveler: Disease on the Silk Roads

If we go back to the second and third centuries C.E. and to the trade routes of the Silk Roads, we find the Chinese Han Dynasty and the Roman Empire suffering large-scale outbreaks of epidemic disease.¹ The most destructive of these diseases were probably smallpox and measles, and epidemics of bubonic plague may also have erupted.² Although these diseases are the most well-known, there were many others. We have long suspected that disease traveled via the Silk Roads; and now we have the proof. Piers Mitchell, a paleopathologist at the University of Cambridge states, “This is the earliest evidence for the spread of infectious diseases along the Silk Road, and the first to find evidence at an archaeological site along the Silk Road itself.”³ Without the technology and medicinal techniques we practice today, the fatalities that these populations suffered were devastating.

The silk roads were an extensive series of trade routes that linked much of Eurasia and north Africa.⁴ The Xuanquanzhi relay station was a well known area along the Silk Roads that housed travelers and relayed messages. It was located in the town of Dunhuang, a key stopping point on the Silk Road within the Hexi Corridor.⁵ Not only were necessities exchanged here, but so were religions, cultures, and the many diseases. Through a study in China conducted by Doctors Hui-Yuan Yeh, Ruillin Mao, Hui Wang, Wuyun Qi, and Piers D. Mitchell, they were able to prove that Chinese liver fluke, roundworm, whipworm, and tapeworm were spread along the Silk Roads.⁶

The study took place in Gansu Province, located in north-west China, which contains the Hexi Corridor.⁷ This corridor formed a section of the Silk Road, an ancient network of thoroughfares extending 4000 miles.⁸

Hygiene sticks were excavated from the latrines at the Xuanquanzhi site in 1992. These sticks were made of wood or bamboo wrapped with cloth, to be used as personal hygiene sticks for wiping.⁹ Out of the many sticks that were collected, seven of them had remnants of fecal matter still attached. The samples were then mixed with distilled water and trisodium phosphate in order for the parasites to be isolated. The most significant finding was the Chinese liver fluke, as it could not have been endemic at Dunhuang, as the parasite requires a wet marshy environment for its life cycle.¹⁰ Due to the discovery of this specific parasite, it proves the argument that the Silk Roads were partly to blame for the mass distribution of diverse diseases. Although there are various ways for diseases to be distributed all over the world, travelers along the Silk Roads provided an easy way for some of the most deadly diseases to travel great distances to devastate two of the largest empires of the ancient world: the Chinese Han Dynasty and the Roman Empire.