̽��ֱ�� of Cambridge - faecal

Ancient faeces provides earliest evidence of infectious disease being carried on Silk Road

fpjl2 — Fri, 22 Jul 2016 09:48:48 +0000

An ancient latrine near a desert in north-western China has revealed the first archaeological evidence that travellers along the Silk Road were responsible for the spread of infectious diseases along huge distances of the route 2,000 years ago.

Cambridge researchers Hui-Yuan Yeh and Piers Mitchell used microscopy to study preserved faeces on ancient ‘personal hygiene sticks’ (used for wiping away faeces from the anus) in the latrine at what was a large Silk Road relay station on the eastern margins of the Tamrin Basin, a region that contains the Taklamakan desert. ̽��ֱ��latrine is thought to date from 111 BC (Han Dynasty) and was in use until 109 AD.

They found that eggs from four species of parasitic worm (helminths) were present: roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura), tapeworm (Taenia sp.), and Chinese liver fluke (Clonorchis sinensis).

Chinese liver fluke is a parasitic flatworm that causes abdominal pain, diarrhoea, jaundice and liver cancer. It requires well-watered, marshy areas to complete its life cycle. Xuanquanzhi relay station was located at the eastern end of the arid Tamrin Basin, an area that contains the fearsome Taklamakan Desert. ̽��ֱ��liver fluke could not have been endemic in this dry region.

In fact, based on the current prevalence of the Chinese liver fluke, its closest endemic area to the latrine’s location in Dunhuang is around 1,500km away, and the species is most common in Guandong Province – some 2,000km from Dunhuang.

Researchers from the ̽��ֱ�� of Cambridge’s Department of Archaeology and Anthropology, who conducted the study, suggest that the traveller infected with this liver fluke must have journeyed an enormous distance, and suggest the discovery provides the first reliable evidence for long distance travel with an infectious disease along the Silk Road.

̽��ֱ��findings are published today in the Journal of Archaeological Science: Reports.

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

̽��ֱ��Silk Road (or Silk Route) came to prominence during the Han Dynasty in China (202 BC – AD 220) as merchants, explorers, soldiers and government officials journeyed between East Asia and the Middle East/Mediterranean region.

Researchers have previously suggested that diseases such as bubonic plague, anthrax and leprosy might have been carried by ancient travellers along the legendary trading route, as similar strains have been found in China and Europe.

“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,” says study lead Piers Mitchell.

̽��ֱ��Cambridge team worked alongside Chinese researchers Ruilin Mao and Hui Wang from the Gansu Institute for Cultural Relics and Archaeology, who originally excavated the ancient latrine and relay station in Ganzu Province.

̽��ֱ��stop was a popular one on the Silk Road with travellers staying there and government officials using the facility to change their horses and deliver letters. While excavating the latrine, the Chinese team found the personal hygiene sticks with cloth wrapped round one end.

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

Inset: Egg of Chinese liver fluke discovered in the latrine at Xuanquanzhi, viewed using microscopy.

Intestinal parasites as well as goods were carried by travellers on iconic route, say researchers examining ancient latrine.

This proves for the first time that travellers along the Silk Road really were responsible for the spread of infectious disease along this route in the past

Piers Mitchell

Hui-Yuan Yeh

2,000-year-old personal hygiene sticks with remains of cloth, excavated from the latrine at Xuanquanzhi

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Opinion: How we discovered infectious diseases in 2,000-year-old faeces from the Silk Road

Anonymous — Thu, 21 Jul 2016 14:17:31 +0000

Once travelled by famous historical figures such as Marco Polo and Genghis Khan, the Silk Road was a hugely important network of transport routes connecting eastern China with Central Asia, the Middle East and Europe. It came to prominence during the Chinese Han Dynasty (202 BC to AD 220) and remained a key transport route for the following 2,000 years.

Given that the Silk Road was a melting pot of people, it is no wonder that researchers have suggested that it might have been responsible for the spread of diseases such as bubonic plague, anthrax and leprosy between China and Europe. However, no one one has yet found any evidence to show how diseases in eastern China reached Europe. Travellers might have spread these diseases taking a southerly route via India and the Middle East, or a northerly route via Mongolia and Russia.

But our team, including researchers at the ̽��ֱ�� of Cambridge and China’s Academy of Social Sciences and Gansu Institute for Cultural Relics and Archaeology, has now found the earliest evidence for the spread of infectious disease organisms along the Silk Road. ̽��ֱ��results have been published in the Journal of Archaeological Science Reports.

Extent of Silk Route/Silk Road. Red is land route and the blue is the sea/water route. NASA/wikimedia

We investigated latrines at the Xuanquanzhi relay station, a fortified stopping point along the Silk Road that was built in 111 BC and used until 109 AD. It is located at Dunhuang, at the eastern end of the Tamrin Basin, an arid region that contacts the fearsome Taklamakan Desert. When the latrines were excavated, the archaeologists found sticks with cloth wrapped around one end (see lead image). These have been described in ancient Chinese texts of the period as a personal hygiene tool for wiping the anus after going to the toilet. Some of the cloth had a dark solid material still adhered to it after all this time.

Faeces under the microscope

We realised that this material was faeces when we looked at it with a high-powered optical microscope. We also found the eggs of four species of parasitic intestinal worms in it. This may seem surprising but the eggs of many species of intestinal worms are very tough and may survive thousands of years in the ground. This indicates that some of the people using this latrine 2,000 years ago were infected with parasites. ̽��ֱ��species included roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura), Taenia sp. tapeworm (likely T. solium, T. asiatica or T. solium) and Chinese liver fluke (Clonorchis sinensis).

Roundworm and whipworm are parasites found right across the world in the past and indicate poor personal hygiene, as the worms are spread by the contamination of food and hands by human faeces. Taenia sp. tapeworm is spread by eating raw or undercooked meat such as pork and beef, and again has been found across large areas of the world in the past.

Meanwhile, Chinese liver fluke – which can cause abdominal pain, diarrhoea, jaundice and liver cancer – is only found in regions of eastern and southern China and Korea, as it has a complex life cycle. It is restricted to areas with wet marshy countryside, as the parasite must pass through the intermediate hosts of a water snail and freshwater fish before it can infect humans. ̽��ֱ��humans have to eat the fish raw if it is to infect them. In modern times, the closest area to Dunhuang where Chinese liver fluke is found is 1,500km away, and the region where most cases of infection are found is 2,000km away.

Egg of Chinese liver fluke discovered in the latrine at Xuanquanzhi, viewed using microscopy. Dimensions 29 x 16 micrometers. ̽��ֱ��Journal of Archaeological Science: Reports., CC BY

Discovering evidence for Chinese liver fluke at a latrine in the arid region of Dunhuang was really exciting. ̽��ֱ��parasite could not possibly be endemic in that region as there are no marshy areas needed for its life cycle. Instead, it shows that a person who became infected with the liver fluke in eastern or southern China was able to travel the huge distance to this relay station along the Silk Road – at least 1,500km.

Our finding suggests that we now know for sure that the Silk Road was responsible for spreading infectious diseases in ancient times. This makes more likely previous proposals that bubonic plague, leprosy and anthrax could also have been spread along it.

Piers Mitchell, Affiliated Lecturer in Biological Anthropology, ̽��ֱ�� of Cambridge

This article was originally published on ̽��ֱ��Conversation. Read the original article.

̽��ֱ��opinions expressed in this article are those of the individual author(s) and do not represent the views of the ̽��ֱ�� of Cambridge.

Piers Mitchell (Department of Biological Anthropology) discusses what we can learn from rummaging around in 2,000-year-old toilets.

Hui-Yuan Yeh

2,000-year-old personal hygiene sticks with remains of cloth, excavated from the latrine at Xuanquanzhi

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Human parasites found in medieval cesspit reveal links between Middle East and Europe

fpjl2 — Thu, 19 Mar 2015 11:58:28 +0000

A new analysis of a medieval cesspit in the Christian quarter of the old city of Jerusalem has revealed the presence of a number of ancient parasite eggs, providing a window into the nature and spread of infectious diseases in the Middle East during the 15th century.

Researchers found evidence of six species of intestinal parasites in the over 500-year-old latrine. These included large quantities of roundworm and whipworm, both spread by faecal contamination of food and thought to be endemic to the region dating back to human evolution out of Africa.

Two of the parasites detected, Entamoeba dysentery and fish tapeworm, were common in northern Europe in the medieval period, but either very rare or almost completely absent among the populations of the medieval Middle East.

̽��ֱ��fish tapeworm was prevalent in northern Europe due to the popularity of fish as a food and the nature of its preparation: often eaten raw, smoked or pickled - which doesn’t kill the parasite. According to Arabic texts of the time, in inland Syrian cities such as Jerusalem fish was not commonly eaten, and when consumed was always cooked thoroughly in accordance with local culinary traditions. This cooking kills the parasite and prevents its spread.

̽��ֱ��team also found pieces of Italian pottery in the same cesspit, reinforcing the hypothesis of strong trading or religious links between Europe and Jerusalem during the late 1400s.

Researchers say the presence of these parasites in the latrine suggests it was either a town house whose owners were Jerusalem merchants that travelled to Europe on business, contracting parasites while there, or it was perhaps a hostel that accommodated European travellers such as merchants or pilgrims.

“While we can only suggest reasons as to why people made these journeys between northern Europe and Jerusalem’s Christian quarter, it does seem they brought with them unsuspecting hitch-hikers in their intestines,” said Dr Piers Mitchell from Cambridge ̽��ֱ��’s Division of Biological Anthropology, who conducted the study, recently published in the International Journal of Paleopathology.

“ ̽��ֱ��presence of the fish tapeworm - which can reach ten metres long in humans, and coils around inside the intestine - combined with the fragments of pottery made in Italy, most likely indicates that travellers from northern Europe used this latrine during a visit to Jerusalem,” Mitchell said.

̽��ֱ��team used a combination of microscopy and biomolecular analysis (ELISA) - to uncover parasite eggs - on 12 ‘coprolites’: fossilised faeces, and some cesspit sediment. ̽��ֱ��cesspit itself, located a short distance north of the Church of the Holy Sepulchre, was much more than a mere hole in the ground - with a vaulted roof, stone-built walls, and two ‘entry chutes’ for defecation on opposing sides.

All 12 coprolites were found to be riddled with both roundworm and whipworm, along with the sediment. These species are thought to have become progressively more common in the region following agriculture, and may have been spread by faecal contamination of food as a consequence of the use of human faeces as a crop fertiliser (as well as poor sanitation).

One coprolite tested positive for eggs of the fish tapeworm, which was the most unexpected discovery from the analysis. ̽��ֱ��researchers also found quantities of Taenia parasite eggs, indicating pork or beef tapeworm. Despite the dominance of Islam in the society during the Mamluk Period (1250-1516 AD), pigs would have still been consumed in the Christian quarter.

Mitchell says the health impacts of these parasites would have varied. “A light load of whipworm or roundworm would be likely to go unnoticed. A heavy load of these parasites in children, however, can lead to malnutrition, reduced intelligence and stunted growth. Dysentery may cause diarrhoea and abdominal cramps for a week or two and then settle, or it may cause death from dehydration and septicaemia.”

“This research highlights how we can use preserved parasite eggs in ancient toilets to spot past migrations and the spread of ancient diseases. Jerusalem’s importance to Christians in medieval Europe made it a key destination for both pilgrimage and trade. We can see these travellers took unexpected guests along with them.”

Inset image: Preserved Whipworm egg found in the medieval Jerusalem latrine. Credit: Hui-Yuan Yeh.

Analysis of a latrine in Jerusalem that dates back over 500 years finds human parasites common in northern Europe yet very rare in Middle East at the time, suggesting long-distance trade or pilgrimage routes and shedding light on prevalent infectious diseases of the age.

Jerusalem’s importance to Christians in medieval Europe made it a key destination for both pilgrimage and trade. We can see these travellers took unexpected guests along with them

Piers Mitchell

Right: Jean-Baptiste Humbert. Left: Hui-Yuan Yeh

Right: excavation deep down into the latrine by the Ecole Biblique de Jerusalem. Left: Taenia tapeworm egg in the latrine indicating either pork or beef tapeworm.

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