Wednesday 1 January 2014

Evidence of parasite infection in a medieval Korean mummy.

Parasite infections have been a fact of life for most humans throughout history, with the medical developments needed to fight them only becoming widely available since the Second World War. Studying the infections found in pre-modern populations is however difficult. Attempts to diagnose infections based upon historical records made by people who lacked the modern medical knowledge to record diagnostic symptoms accurately are an interesting parlour game, but not very scientific. Studying parasite infections in preserved human remains is a more reliable approach, but while their have been some well documented cases where infections have been studied in exceptionally well preserved remains, such as Egyptian mummies, for most ancient populations such remains are not available.

In a paper published in the Journal of Archaeological Science in January 2012, a team of scientists led by Dong Hoon Shin of the Institute of Forensic Medicine and Department of Anatomy at Seoul National University College of Medicine, describe the recovery of parasite eggs and DNA from a poorly preserved medieval mummy from a Joseon (Korean State that existed from 1392 till 1997) tomb at Waegwan on the southern Korean Peninsula.

The mummy was a man who lived from 1624 till 1685. He was semi-mummified and wrapped in burial cloths within a coffin, in a tomb that was excavated in October 2008. The skeleton was well preserved, as were tissues on the head and some parts of the body, however the abdomen area had largely decomposed to sediment. 

Textile experts removed the clothes from the Waegwan mummy, wearing the sterilized clothes. Dong et al. (2013).

Sediments from around the hip were collected and sifted for parasite eggs. Two species were recovered, Clonorchis sinensis (the Chinese Liver Fluke) and Trichuris trichiura (the Trichuriasis Roundworm or Whipworm). The sediment were also analysed for the presence of DNA from known parasites, with that of Clonorchis sinensis being recovered.

 The hip of the Waegwan mummy, asterisk showing the area from which sediment was collected for analysis. Dong et al. (2013).

The presence of these parasites is not a great surprise. Clonorchis sinensis is known to have been more-or-less ubiquitous in Korea as recently as the 1970s, and is spread by the eating of raw fish, a longstanding part of the Korean diet, and Trichuris trichiura, is spread directly from human feces to soil and then on to new human hosts, and was very widespread in Asian populations until quite recently. However the recovery of DNA from a 300-year-old decomposed corpse, combined with the presence of eggs of the same species (which indicates the DNA evidence is reliable), suggests that the technique used for DNA recovery has the potential to reveal the presence of parasites in other ancient burials.

Parasite eggs recovered from the Waegwan mummy. Dong et al. (2013).

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