AUG 07, 2016 10:03 AM PDT

Infectious Disease in the Ancient World: Parasites on the Silk Road

WRITTEN BY: Carmen Leitch
The Silk Road has been implicated in the transmission of infectious disease, and it’s no longer an educated guess. The analysis of an ancient latrine in a desert in Northwestern China has provided evidence that travelers carried parasites in their bodies along the journey. The video below explains.

In a study published in the Journal of Archaeological Science: Reports, researchers at Cambridge University found eggs from parasitic worms on “personal hygiene sticks” taken from that old toilet on the eastern margins of the Tamrin Basin, an area that encompasses the Taklamakan desert. It’s estimated that the latrine dates from 111 B.C., and was in use until 109 A.D. One must unfortunately consider what people had to do before toilet paper existed. It was common for sponges or cloth wrapped around sticks to be used to wipe away a mess after your business was done. Those sticks stuck around, to be found and analyzed some 2,000 years later.
These are 2,000-year-old personal hygiene sticks with remains of cloth, excavated from the latrine at Xuanquanzhi. / Credit: Hui-Yuan Yeh. Reproduced from the Journal of Archaeological Science: Reports
Using microscopy, Hui-Yuan Yeh and Piers Mitchell found eggs from the roundworm (Ascaris lumbricoides), tapeworm (Taenia sp.), whipworm (Trichuris trichiura), and Chinese liver fluke (Clonorchis sinensis). Chinese liver fluke specifically requires marshy areas with abundant moisture for the successful completion of its life cycle. Because the eastern end of the Tamrin Basin is a dry, arid place with a desert, the liver fluke would not have been endemic in this region. The current closest endemic area of this fluke is around 1,500 kilometers away.
The current site where liver fluke is found is nowhere near the location on the Silk Road (red dot) where it's eggs were identified. / Credit: Yeh et al. Reproduced from the Journal of Archaeological Science: Reports
Chinese scientists Ruilin Mao and Hui Wang of the Gansu Institute for Cultural Relics and Archaeology originally excavated the latrine and accompanying relay station in Ganzu Province. They worked with researchers at University of Cambridge's Department of Archaeology and Anthropology who led the study, propose that a traveller that was infected with the liver fluke probably journeyed over a vast distance, and posit that their discovery is the first concrete evidence that infectious diseases were carried a long way by people traversing the extensive Silk Road.

"When I first saw the Chinese liver fluke egg down the microscope I knew that we had made a momentous discovery," said one of the investigators, Hui-Yuan Yeh. "Our study is the first to use archaeological evidence from a site on the Silk Road to demonstrate that travelers were taking infectious diseases with them over these huge distances."

It’s long been suggested that dangerous diseases like bubonic plague, anthrax and leprosy could have been carried by ancient travelers along the route, because strains found in China and Europe have similarities. The legendary trade route was in its heyday during the time of China’s Han Dynasty (210 B.C. - 220 A.D.).

"Until now there has been no proof that the Silk Road was responsible for the spread of infectious diseases. They could instead have spread between China and Europe via India to the south, or via Mongolia and Russia to the north," explained study leader Piers Mitchell.

"Finding evidence for this species in the latrine indicates that a traveler had come here from a region of China with plenty of water, where the parasite was endemic. This proves for the first time that travelers along the Silk Road really were responsible for the spread of infectious disease along this route in the past,” concluded Mitchell.

Sources: AAAS/Eurekalert! via University of Cambridge, Journal of Archaeological Science: Reports
About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
SEP 01, 2020
Cell & Molecular Biology
Smell Cells Are Especially Good at Fighting the Flu
SEP 01, 2020
Smell Cells Are Especially Good at Fighting the Flu
All over the body, cells line organs and vessels, forming protective barriers. But pathogens like the flu have gained th ...
SEP 28, 2020
Microbiology
The Flu Vaccine Will Not Increase the Risk of COVID-19
SEP 28, 2020
The Flu Vaccine Will Not Increase the Risk of COVID-19
Scientists and clinicians want people to get their flu shots this year, especially because of the ongoing pandemic.
OCT 18, 2020
Cell & Molecular Biology
Small RNA is Connected to Bacterial Pathogenicity
OCT 18, 2020
Small RNA is Connected to Bacterial Pathogenicity
It's thought that as much as half of the global population carries a bacterium called Helicobacter pylori in their stoma ...
OCT 26, 2020
Microbiology
A Network of Fungi Helps Trees Grow
OCT 26, 2020
A Network of Fungi Helps Trees Grow
Trees rely on a network of fungal friends for good health. Communities of trees can share nutrients and other essentail ...
NOV 05, 2020
Clinical & Molecular DX
Painless Microneedle Patch Diagnoses Malaria in Minutes
NOV 05, 2020
Painless Microneedle Patch Diagnoses Malaria in Minutes
It looks like a Band-Aid — a small, adhesive patch that is applied directly to the skin. This simple, low-cost dia ...
NOV 06, 2020
Microbiology
Daily Aspirin Users Less Likely to Die From COVID-19
NOV 06, 2020
Daily Aspirin Users Less Likely to Die From COVID-19
Recent work has backed up research from earlier this year that suggested that aspirin might help prevent the worst cases ...
Loading Comments...